1
|
Yan WH, Tang N, Xu HT, Tang J, Liu LY, Shah S, Ma M, Elgizawy KK, Huang Q, Wu G, Yang FL. Diallyl Trisulfide, an Active Substance from Garlic, Inhibits Female Oviposition by Decreasing the Expression of the OCT Gene, which is Highly Expressed in the Spermathecal Gland of Sitotroga cerealella (Oliver). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2025; 73:10974-10984. [PMID: 40146659 DOI: 10.1021/acs.jafc.4c11952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2025]
Abstract
Diallyl trisulfide (DAT) effectively inhibits the fecundity of Sitotroga cerealella. Organic cation transporter (OCT) was most highly expressed in the spermathecal gland of female moths and was significantly decreased after DAT fumigation. However, the function of OCT in insect reproduction has been rarely reported. In this study, after silencing OCT in female adults, the mating rate, oviposition, and number of sperm transferred to females were decreased significantly, and transfer time of sperm in the female was delayed. Meanwhile, the long and short waves formed during sperm movement became longer, which lead sperm to take a longer time to complete a movement cycle. Finally, 5-hydroxytryptamine (5-HT) was significantly increased. Conversely, triacylglycerol (TG) decreased significantly. The expression of the 5-HT 2A receptor gene, which is highly expressed in the abdomen, was significantly decreased. The findings have provided a theoretical basis for explaining the inhibitory effect of garlic essential oil on the reproduction of S. cerealella.
Collapse
Affiliation(s)
- Wen-Han Yan
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Ning Tang
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Hui-Ting Xu
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Jie Tang
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Lian-Yun Liu
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Sakhawat Shah
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Min Ma
- Institute of Disinfection and Vector Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang 315010, PR China
| | - Karam Khamis Elgizawy
- Plant Protection Department, Faculty of Agriculture, Benha University, Moshtohor, Toukh 13736, Egypt
| | - Qiuying Huang
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Gang Wu
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Feng-Lian Yang
- Hubei Key Laboratory of Insect Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| |
Collapse
|
2
|
Chen YC, Zang KE, Ahamed H, Ringstad N. Food sensing controls C. elegans reproductive behavior by neuromodulatory disinhibition. SCIENCE ADVANCES 2025; 11:eadu5829. [PMID: 40238881 PMCID: PMC12002139 DOI: 10.1126/sciadv.adu5829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2024] [Accepted: 03/07/2025] [Indexed: 04/18/2025]
Abstract
Like many organisms, the roundworm Caenorhabditis elegans incorporates an assessment of environmental quality into its reproductive strategy. C. elegans hermaphrodites release fertilized eggs into food-rich environments but retain them in the absence of food. Here, we report the discovery of a neural circuit required for the modulation of reproductive behavior by food sensing. A mutation that electrically silences the AVK interneurons uncouples egg laying from detection of environmental food cues. We find that AVK activity inhibits egg laying, and AVKs themselves are inhibited by dopamine released from food-sensing neurons. AVKs express a large number of structurally and functionally diverse neuropeptides. Coordination of food-sensing and reproductive behavior requires a subset of AVK neuropeptides that converge on a small ensemble of premotor neurons that coexpress their cognate receptors. Modulation of C. elegans reproductive behavior, therefore, requires a cascade of neuromodulatory signals that uses disinhibition and combinatorial neuropeptide signals to activate reproductive behavior when food is sensed.
Collapse
Affiliation(s)
| | - Kara E. Zang
- Department of Cell Biology and Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Hassan Ahamed
- Department of Cell Biology and Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Niels Ringstad
- Department of Cell Biology and Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| |
Collapse
|
3
|
Yan L, Claman A, Bode A, Collins KM. The C. elegans uv1 Neuroendocrine Cells Provide Mechanosensory Feedback of Vulval Opening. J Neurosci 2025; 45:e0678242024. [PMID: 39788737 PMCID: PMC11800740 DOI: 10.1523/jneurosci.0678-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 12/10/2024] [Accepted: 12/29/2024] [Indexed: 01/12/2025] Open
Abstract
Neuroendocrine cells react to physical, chemical, and synaptic signals originating from tissues and the nervous system, releasing hormones that regulate various body functions beyond the synapse. Neuroendocrine cells are often embedded in complex tissues making direct tests of their activation mechanisms and signaling effects difficult to study. In the nematode worm Caenorhabditis elegans, four uterine-vulval (uv1) neuroendocrine cells sit above the vulval canal next to the egg-laying circuit, releasing tyramine and neuropeptides that feedback to inhibit egg laying. We have previously shown uv1 cells are mechanically deformed during egg laying, driving uv1 Ca2+ transients. However, whether egg-laying circuit activity, vulval opening, and/or egg release triggered uv1 Ca2+ activity was unclear. Here, we show uv1 responds directly to mechanical activation. Optogenetic vulval muscle stimulation triggers uv1 Ca2+ activity following muscle contraction even in sterile animals. Direct mechanical prodding with a glass probe placed against the worm cuticle triggers robust uv1 Ca2+ activity similar to that seen during egg laying. Direct mechanical activation of uv1 cells does not require other cells in the egg-laying circuit, synaptic or peptidergic neurotransmission, or transient receptor potential vanilloid and Piezo channels. EGL-19 L-type Ca2+ channels, but not P/Q/N-type or ryanodine receptor Ca2+ channels, promote uv1 Ca2+ activity following mechanical activation. L-type channels also facilitate the coordinated activation of uv1 cells across the vulva, suggesting mechanical stimulation of one uv1 cell cross-activates the other. Our findings show how neuroendocrine cells like uv1 report on the mechanics of tissue deformation and muscle contraction, facilitating feedback to local circuits to coordinate behavior.
Collapse
Affiliation(s)
- Lijie Yan
- Department of Biology, University of Miami, Coral Gables, Florida 33143
| | - Alexander Claman
- Department of Biology, University of Miami, Coral Gables, Florida 33143
| | - Addys Bode
- Department of Biology, University of Miami, Coral Gables, Florida 33143
| | - Kevin M Collins
- Department of Biology, University of Miami, Coral Gables, Florida 33143
| |
Collapse
|
4
|
Perry JA, Werner ME, Omi S, Heck BW, Maddox PS, Mavrakis M, Maddox AS. Animal septins contain functional transmembrane domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2023.11.20.567915. [PMID: 38045322 PMCID: PMC10690161 DOI: 10.1101/2023.11.20.567915] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Septins, a conserved family of filament-forming proteins, contribute to eukaryotic cell division, polarity, and membrane trafficking. Septins scaffold other proteins to cellular membranes, but it is not fully understood how septins associate with membranes. We identified and characterized an isoform of Caenorhabditis elegans septin UNC-61 that was predicted to contain a transmembrane domain (TMD). The TMD isoform is expressed in a subset of tissues where the known septins were known to act, and TMD function was required for tissue integrity of the egg-laying apparatus. We found predicted TMD-containing septins across much of opisthokont phylogeny and demonstrated that the TMD-containing sequence of a primate TMD-septin is sufficient for localization to cellular membranes. Together, our findings reveal a novel mechanism of septin-membrane association with profound implications for septin dynamics and regulation.
Collapse
Affiliation(s)
- Jenna A. Perry
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Michael E. Werner
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Shizue Omi
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Med, 13013 Marseille, France
| | - Bryan W. Heck
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Paul S. Maddox
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| | - Manos Mavrakis
- Institut Fresnel, CNRS UMR7249, Aix Marseille Univ, Centrale Med, 13013 Marseille, France
| | - Amy S. Maddox
- Department of Biology, The University of North Carolina at Chapel Hill; Chapel Hill, North Carolina, 27599 USA
| |
Collapse
|
5
|
Almoril-Porras A, Calvo AC, Niu L, Beagan J, Díaz García M, Hawk JD, Aljobeh A, Wisdom EM, Ren I, Wang ZW, Colón-Ramos DA. Configuration of electrical synapses filters sensory information to drive behavioral choices. Cell 2025; 188:89-103.e13. [PMID: 39742807 DOI: 10.1016/j.cell.2024.11.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 07/26/2024] [Accepted: 11/27/2024] [Indexed: 01/04/2025]
Abstract
Synaptic configurations underpin how the nervous system processes sensory information to produce a behavioral response. This is best understood for chemical synapses, and we know far less about how electrical synaptic configurations modulate sensory information processing and context-specific behaviors. We discovered that innexin 1 (INX-1), a gap junction protein that forms electrical synapses, is required to deploy context-specific behavioral strategies underlying thermotaxis behavior in C. elegans. Within this well-defined circuit, INX-1 couples two bilaterally symmetric interneurons to integrate sensory information during migratory behavior across temperature gradients. In inx-1 mutants, uncoupled interneurons display increased excitability and responses to subthreshold sensory stimuli due to increased membrane resistance and reduced membrane capacitance, resulting in abnormal responses that extend run durations and trap the animals in context-irrelevant tracking of isotherms. Thus, a conserved configuration of electrical synapses enables differential processing of sensory information to deploy context-specific behavioral strategies.
Collapse
Affiliation(s)
- Agustin Almoril-Porras
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Ana C Calvo
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Longgang Niu
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Jonathan Beagan
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Malcom Díaz García
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Josh D Hawk
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Ahmad Aljobeh
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Elias M Wisdom
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Ivy Ren
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Daniel A Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA; Wu Tsai Institute, Yale University, New Haven, CT 06510, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA; Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan 00901, Puerto Rico.
| |
Collapse
|
6
|
Medrano E, Jendrick K, McQuirter J, Moxham C, Rajic D, Rosendorf L, Stilman L, Wilright D, Collins KM. Osmolarity regulates C. elegans egg-laying behavior via parallel chemosensory and biophysical mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.12.30.630790. [PMID: 39803577 PMCID: PMC11722301 DOI: 10.1101/2024.12.30.630790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2025]
Abstract
Animals alter their behavior in response to changes in the environment. Upon encountering hyperosmotic conditions, the nematode worm C. elegans initiates avoidance and cessation of egg-laying behavior. While the sensory pathway for osmotic avoidance is well-understood, less is known about how egg laying is inhibited. We analyzed egg-laying behavior after acute and chronic shifts to and from hyperosmotic media. Animals on 400 mM sorbitol stop laying eggs immediately but then resume ~3 hours later, after accumulating additional eggs in the uterus. Surprisingly, the hyperosmotic cessation of egg laying did not require known osmotic avoidance signaling pathways. Acute hyperosmotic shifts in hyperosmotic-resistant mutants overproducing glycerol also blocked egg laying, but these animals resumed egg laying more quickly than similarly treated wild-type animals. These results suggest that hyperosmotic conditions disrupt a 'high-inside' hydrostatic pressure gradient required for egg laying. Consistent with this hypothesis, animals adapted to hyperosmotic conditions laid more eggs after acute shifts back to normosmic conditions. Optogenetic stimulation of the HSN egg-laying command neurons in hyper-osmotic treated animals led to fewer and slower egg-laying events, an effect not seen following direct optogenetic stimulation of the postsynaptic vulval muscles. Hyperosmotic conditions also affected egg-laying circuit activity with the vulval muscles showing reduced Ca2+ transient amplitudes and frequency even after egg-laying resumes. Together, these results indicate that hyperosmotic conditions regulate egg-laying via two parallel mechanisms: a sensory pathway that acts to reduce HSN excitability and neurotransmitter release, and a biophysical mechanism where a hydrostatic pressure gradient reports egg accumulation in the uterus.
Collapse
Affiliation(s)
- Emmanuel Medrano
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
| | - Karen Jendrick
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Julian McQuirter
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Claire Moxham
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Dominique Rajic
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Lila Rosendorf
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Liraz Stilman
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Dontrel Wilright
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
- These authors contributed equally and are listed in alphabetical order
| | - Kevin M Collins
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146
| |
Collapse
|
7
|
Riboul DV, Crill S, Oliva CD, Restifo MG, Joseph R, Joseph K, Nguyen KC, Hall DH, Fily Y, Macleod GT. Ultrastructural Analysis Reveals Mitochondrial Placement Independent of Synapse Placement in Fine Caliber C. elegans Neurons. J Comp Neurol 2024; 532:e70002. [PMID: 39690920 PMCID: PMC11977862 DOI: 10.1002/cne.70002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 10/18/2024] [Accepted: 11/15/2024] [Indexed: 12/19/2024]
Abstract
Neurons rely on mitochondria for an efficient supply of ATP and other metabolites. However, while neurons are highly elongated, mitochondria are discrete and limited in number. Due to the slow rates of metabolite diffusion over long distances, it follows that neurons would benefit from an ability to control the distribution of mitochondria to sites of high metabolic activity such as synapses. Ultrastructural data over substantial portions of a neuron's extent that would allow for tests of such hypotheses are scarce. Here, we mined the Caenorhabditis elegans' electron micrographs of John White and Sydney Brenner and found systematic differences in average mitochondrial length (ranging from 1.3 to 2.4 µm), diameter (0.18-0.24 µm) and volume density (3.7%-6.5%) between neurons of different function and neurotransmitter type, but found limited differences in mitochondrial length, diameter, and density between axons and dendrites of the same neurons. In analyses of mitochondrial distribution, mitochondria were found to be distributed randomly with respect to presynaptic sites. Presynaptic sites were primarily localized to varicosities, but mitochondria were no more likely to be found in synaptic varicosities than non-synaptic varicosities. Consistently, mitochondrial volume density was no greater in synaptic varicosities than non-synaptic varicosities. Therefore, beyond the capacity to disperse mitochondria throughout their length, at least in C. elegans, fine caliber neurons manifest limited subcellular control of mitochondrial size and distribution.
Collapse
Affiliation(s)
- Danielle V. Riboul
- Integrative Biology & Neuroscience Graduate Program, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Sarah Crill
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Carlos D. Oliva
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL, 33458, USA
| | | | - Reggie Joseph
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Kerdes Joseph
- Department of Biology, C.E.S. College of Science, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Ken C.Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yaouen Fily
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Gregory T. Macleod
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL, 33458, USA
- Jupiter Life Sciences Initiative, Florida Atlantic University, Jupiter, FL 33458, USA
- Brain Institute, Florida Atlantic University, Jupiter, FL 33458, USA
- Institute for Human Health & Disease Intervention (I-HEALTH), Florida Atlantic University, Jupiter, FL 33458, USA
| |
Collapse
|
8
|
Watteyne J, Chudinova A, Ripoll-Sánchez L, Schafer WR, Beets I. Neuropeptide signaling network of Caenorhabditis elegans: from structure to behavior. Genetics 2024; 228:iyae141. [PMID: 39344922 PMCID: PMC11538413 DOI: 10.1093/genetics/iyae141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Accepted: 08/19/2024] [Indexed: 10/01/2024] Open
Abstract
Neuropeptides are abundant signaling molecules that control neuronal activity and behavior in all animals. Owing in part to its well-defined and compact nervous system, Caenorhabditis elegans has been one of the primary model organisms used to investigate how neuropeptide signaling networks are organized and how these neurochemicals regulate behavior. We here review recent work that has expanded our understanding of the neuropeptidergic signaling network in C. elegans by mapping the evolutionary conservation, the molecular expression, the receptor-ligand interactions, and the system-wide organization of neuropeptide pathways in the C. elegans nervous system. We also describe general insights into neuropeptidergic circuit motifs and the spatiotemporal range of peptidergic transmission that have emerged from in vivo studies on neuropeptide signaling. With efforts ongoing to chart peptide signaling networks in other organisms, the C. elegans neuropeptidergic connectome can serve as a prototype to further understand the organization and the signaling dynamics of these networks at organismal level.
Collapse
Affiliation(s)
- Jan Watteyne
- Department of Biology, University of Leuven, Leuven 3000, Belgium
| | | | - Lidia Ripoll-Sánchez
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- Department of Psychiatry, Cambridge University, Cambridge CB2 0SZ, UK
| | - William R Schafer
- Department of Biology, University of Leuven, Leuven 3000, Belgium
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Isabel Beets
- Department of Biology, University of Leuven, Leuven 3000, Belgium
| |
Collapse
|
9
|
Lo JY, Adam KM, Garrison JL. Neuropeptide inactivation regulates egg-laying behavior to influence reproductive health in Caenorhabditis elegans. Curr Biol 2024; 34:4715-4728.e4. [PMID: 39395417 PMCID: PMC12009563 DOI: 10.1016/j.cub.2024.09.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 07/11/2024] [Accepted: 09/23/2024] [Indexed: 10/14/2024]
Abstract
Neural communication requires both fast-acting neurotransmitters and neuromodulators that function on slower timescales to communicate. Endogenous bioactive peptides, often called "neuropeptides," comprise the largest and most diverse class of neuromodulators that mediate crosstalk between the brain and peripheral tissues to regulate physiology and behaviors conserved across the animal kingdom. Neuropeptide signaling can be terminated through receptor binding and internalization or degradation by extracellular enzymes called neuropeptidases. Inactivation by neuropeptidases can shape the dynamics of signaling in vivo by specifying both the duration of signaling and the anatomic path neuropeptides can travel before they are degraded. For most neuropeptides, the identity of the relevant inactivating peptidase(s) is unknown. Here, we established a screening platform in C. elegans utilizing mass spectrometry-based peptidomics to discover neuropeptidases and simultaneously profile the in vivo specificity of these enzymes against each of more than 250 endogenous peptides. We identified NEP-2, a worm ortholog of the mammalian peptidase neprilysin-2, and demonstrated that it regulates specific neuropeptides, including those in the egg-laying circuit. We found that NEP-2 is required in muscle cells to regulate signals from neurons to modulate both behavior and health in the reproductive system. Taken together, our results demonstrate that peptidases, which are an important node of regulation in neuropeptide signaling, affect the dynamics of signaling to impact behavior, physiology, and aging.
Collapse
Affiliation(s)
- Jacqueline Y Lo
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945, USA
| | - Katelyn M Adam
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945, USA; Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089, USA
| | - Jennifer L Garrison
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945, USA; Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089, USA; Cellular and Molecular Pharmacology, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA; Center for Healthy Aging in Women, 8001 Redwood Boulevard, Novato, CA 94945, USA; Productive Health Global Consortium, 8001 Redwood Boulevard, Novato, CA 94945, USA.
| |
Collapse
|
10
|
Butt A, Van Damme S, Santiago E, Olson A, Beets I, Koelle MR. Neuropeptide and serotonin co-transmission sets the activity pattern in the C. elegans egg-laying circuit. Curr Biol 2024; 34:4704-4714.e5. [PMID: 39395419 DOI: 10.1016/j.cub.2024.07.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/08/2024] [Accepted: 07/17/2024] [Indexed: 10/14/2024]
Abstract
Neurons typically release both a neurotransmitter and one or more neuropeptides, but how these signals are integrated within neural circuits to generate and tune behaviors remains poorly understood. We studied how the two hermaphrodite-specific neurons (HSNs) activate the egg-laying circuit of Caenorhabditis elegans by releasing both the neurotransmitter serotonin and NLP-3 neuropeptides. Egg laying occurs in a temporal pattern with approximately 2-min active phases, during which eggs are laid, separated by approximately 20-min inactive phases, during which no eggs are laid. To understand how serotonin and NLP-3 neuropeptides together help produce this behavior pattern, we identified the G-protein-coupled receptor neuropeptide receptor 36 (NPR-36) as an NLP-3 neuropeptide receptor using genetic and molecular experiments. We found that NPR-36 is expressed in, and promotes egg laying within, the egg-laying muscle cells, the same cells where two serotonin receptors also promote egg laying. During the active phase, when HSN activity is high, we found that serotonin and NLP-3 neuropeptides each have a different effect on the timing of egg laying. During the inactive phase, HSN activity is low, which may result in release of only serotonin, yet mutants lacking either serotonin or nlp-3 signaling have longer inactive phases. This suggests that NLP-3 peptide signaling may persist through the inactive phase to help serotonin signaling terminate the inactive phase. We propose a model for neural circuit function in which multiple signals with short- and long-lasting effects compete to generate and terminate persistent internal states, thus patterning a behavior over tens of minutes.
Collapse
Affiliation(s)
- Allison Butt
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06510, USA
| | | | - Emerson Santiago
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06510, USA
| | - Andrew Olson
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Isabel Beets
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06510, USA.
| |
Collapse
|
11
|
Liu J, Bonnard E, Scholz M. Adapting and optimizing GCaMP8f for use in Caenorhabditis elegans. Genetics 2024; 228:iyae125. [PMID: 39074213 PMCID: PMC11457936 DOI: 10.1093/genetics/iyae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/17/2024] [Accepted: 07/17/2024] [Indexed: 07/31/2024] Open
Abstract
Improved genetically encoded calcium indicators (GECIs) are essential for capturing intracellular dynamics of both muscle and neurons. A novel set of GECIs with ultrafast kinetics and high sensitivity was recently reported by Zhang et al. (2023). While these indicators, called jGCaMP8, were demonstrated to work in Drosophila and mice, data for Caenorhabditis elegans were not reported. Here, we present an optimized construct for C. elegans and use this to generate several strains expressing GCaMP8f (fast variant of the indicator). Utilizing the myo-2 promoter, we compare pharyngeal muscle activity measured with GCaMP7f and GCaMP8f and find that GCaMP8f is brighter upon binding to calcium, shows faster kinetics, and is not disruptive to the intrinsic contraction dynamics of the pharynx. Additionally, we validate its application for detecting neuronal activity in touch receptor neurons which reveals robust calcium transients even at small stimulus amplitudes. As such, we establish GCaMP8f as a potent tool for C. elegans research which is capable of extracting fast calcium dynamics at very low magnifications across multiple cell types.
Collapse
Affiliation(s)
- Jun Liu
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
| | - Elsa Bonnard
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
- International Max Planck Research School for Brain and Behavior, Bonn 53175, Germany
| | - Monika Scholz
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
| |
Collapse
|
12
|
Peesapati RS, Austin-Byler BL, Nawaz FZ, Stevenson JB, Mais SA, Kaya RN, Hassan MG, Khanal N, Wells AC, Ghiai D, Garikapati AK, Selhub J, Kipreos ET. A specific folate activates serotonergic neurons to control C. elegans behavior. Nat Commun 2024; 15:8471. [PMID: 39349491 PMCID: PMC11442744 DOI: 10.1038/s41467-024-52738-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 09/19/2024] [Indexed: 10/02/2024] Open
Abstract
Folates are B-group vitamins that function in one-carbon metabolism. Here we show that a specific folate can activate serotonergic neurons in C. elegans to modulate behavior through a pathway that requires the folate receptor FOLR-1 and the GON-2 calcium channel. FOLR-1 and GON-2 physically interact in a heterologous system, and both are expressed in the HSN and NSM serotonergic neurons. Both the folate 10-formyl-THF and a non-metabolic pteroate induce increases in the number of Ca2+ transients in the HSN neurons and egg laying in an FOLR-1- and GON-2-dependent manner. FOLR-1 and GON-2 are required for the activation of the NSM neurons in response to 10-formyl-THF, and for full NSM-mediated stoppage of movement when starved animals encounter bacteria. Our results demonstrate that FOLR-1 acts independently of one-carbon metabolism and suggest that 10-formyl-THF acts as a dietary signal that activates serotonergic neurons to impact behavior through a pathway that involves calcium entry.
Collapse
Affiliation(s)
- Ria S Peesapati
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | | | | | | | - Stanelle A Mais
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Rabia N Kaya
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Michael G Hassan
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Nabraj Khanal
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Alexandra C Wells
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Deena Ghiai
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Anish K Garikapati
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA
| | - Jacob Selhub
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - Edward T Kipreos
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA.
| |
Collapse
|
13
|
Li R, Huang X, Shen L, Zhang T, Liu N, Hou X, Wong G. Novel C. elegans models of Lewy body disease reveal pathological protein interactions and widespread miRNA dysregulation. Cell Mol Life Sci 2024; 81:377. [PMID: 39212733 PMCID: PMC11364739 DOI: 10.1007/s00018-024-05383-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 06/27/2024] [Accepted: 07/26/2024] [Indexed: 09/04/2024]
Abstract
Lewy body diseases (LBD) comprise a group of complex neurodegenerative conditions originating from accumulation of misfolded alpha-synuclein (α-syn) in the form of Lewy bodies. LBD pathologies are characterized by α-syn deposition in association with other proteins such as Amyloid β (Aβ), Tau, and TAR-DNA-binding protein. To investigate the complex interactions of these proteins, we constructed 2 novel transgenic overexpressing (OE) C. elegans strains (α-synA53T;Taupro-agg (OE) and α-synA53T;Aβ1-42;Taupro-agg (OE)) and compared them with previously established Parkinson's, Alzheimer's, and Lewy Body Dementia disease models. The LBD models presented here demonstrate impairments including uncoordinated movement, egg-laying deficits, altered serotonergic and cholinergic signaling, memory and posture deficits, as well as dopaminergic neuron damage and loss. Expression levels of total and prone to aggregation α-syn protein were increased in α-synA53T;Aβ1-42 but decreased in α-synA53T;Taupro-agg animals when compared to α-synA53T animals suggesting protein interactions. These alterations were also observed at the mRNA level suggesting a pre-transcriptional mechanism. miRNA-seq revealed that cel-miR-1018 was upregulated in LBD models α-synA53T, α-synA53T;Aβ1-42, and α-synA53T;Taupro-agg compared with WT. cel-miR-58c was upregulated in α-synA53T;Taupro-agg but downregulated in α-synA53T and α-synA53T;Aβ1-42 compared with WT. cel-miR-41-3p and cel-miR-355-5p were significantly downregulated in 3 LBD models. Our results obtained in a model organism provide evidence of interactions between different pathological proteins and alterations in specific miRNAs that may further exacerbate or ameliorate LBD pathology.
Collapse
Affiliation(s)
- Rongzhen Li
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
| | - Xiaobing Huang
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
- College of Pharmacy, Shenzhen Technology University, Shenzhen, 518118, China
| | - Linjing Shen
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Tianjiao Zhang
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
- School of Pharmacy and Food Engineering, Wuyi University, Jiangmen, 529020, China
| | - Ning Liu
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
| | - Xiangqing Hou
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China
- Guangzhou National Laboratory, Guangzhou International Bio Island, Guangzhou, 510005, China
| | - Garry Wong
- Cancer Centre, Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, E12-3005 Avenida da Universidade, Macau, 999078, China.
| |
Collapse
|
14
|
Kong JN, Dipon Ghosh D, Savvidis A, Sando SR, Droste R, Robert Horvitz H. Transcriptional landscape of a hypoxia response identifies cell-specific pathways for adaptation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.02.601765. [PMID: 39005398 PMCID: PMC11245032 DOI: 10.1101/2024.07.02.601765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
How the HIF-1 (Hypoxia-Inducible) transcription factor drives and coordinates distinct responses to low oxygen across diverse cell types is poorly understood. We present a multi-tissue single-cell gene-expression atlas of the hypoxia response of the nematode Caenorhabditis elegans . This atlas highlights how cell-type-specific HIF-1 responses overlap and diverge among and within neuronal, intestinal, and muscle tissues. Using the atlas to guide functional analyses of candidate muscle-specific HIF-1 effectors, we discovered that HIF-1 activation drives downregulation of the tspo-1 ( TSPO, Translocator Protein) gene in vulval muscle cells to modulate a hypoxia-driven change in locomotion caused by contraction of body-wall muscle cells. We further showed that in human cardiomyocytes HIF-1 activation decreases levels of TSPO and thereby alters intracellular cholesterol transport and the mitochondrial network. We suggest that TSPO-1 is an evolutionarily conserved mediator of HIF-1-dependent modulation of muscle and conclude that our gene-expression atlas can help reveal how HIF-1 drives cell-specific adaptations to hypoxia.
Collapse
|
15
|
Aprison EZ, Dzitoyeva S, Ruvinsky I. The roles of TGFβ and serotonin signaling in regulating proliferation of oocyte precursors and germline aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593208. [PMID: 38766220 PMCID: PMC11100717 DOI: 10.1101/2024.05.08.593208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The decline of oocyte quality in aging but otherwise relatively healthy individuals compels a search for underlying mechanisms. Building upon a finding that exposure to male pheromone ascr#10 improves oocyte quality in C. elegans, we uncovered a regulatory cascade that promotes proliferation of oocyte precursors in adults and regulates oocyte quality. We found that the male pheromone promotes proliferation of oocyte precursors by upregulating LAG-2, a ligand of the Notch-like pathway in the germline stem cell niche. LAG-2 is upregulated by a TGFβ-like ligand DAF-7 revealing similarity of regulatory mechanisms that promote germline proliferation in adults and larvae. A serotonin circuit that also regulates food search and consumption upregulates DAF-7 specifically in adults. The serotonin/DAF-7 signaling promotes germline expansion to compensate for oocyte expenditure which is increased by the male pheromone. Finally, we show that the earliest events in reproductive aging may be due to declining expression of LAG-2 and DAF-7. Our findings highlight neuronal signals that promote germline proliferation in response to the environment and argue that deteriorating oocyte quality may be due to reduced neuronal expression of key germline regulators.
Collapse
Affiliation(s)
- Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
16
|
Leonetti P, Dallera D, De Marchi D, Candito P, Pasotti L, Macovei A. Exploring the putative microRNAs cross-kingdom transfer in Solanum lycopersicum-Meloidogyne incognita interactions. FRONTIERS IN PLANT SCIENCE 2024; 15:1383986. [PMID: 38784062 PMCID: PMC11114104 DOI: 10.3389/fpls.2024.1383986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024]
Abstract
Introduction Plant-pathogen interaction is an inexhaustible source of information on how to sustainably control diseases that negatively affect agricultural production. Meloidogyne incognita is a root-knot nematode (RKN), representing a pest for many crops, including tomato (Solanum lycopersicum). RKNs are a global threat to agriculture, especially under climate change, and RNA technologies offer a potential alternative to chemical nematicides. While endogenous microRNAs have been identified in both S. lycopersicum and M. incognita, and their roles have been related to the regulation of developmental changes, no study has investigated the miRNAs cross-kingdom transfer during this interaction. Methods Here, we propose a bioinformatics pipeline to highlight potential miRNA-dependent cross-kingdom interactions between tomato and M. incognita. Results The obtained data show that nematode miRNAs putatively targeting tomato genes are mostly related to detrimental effects on plant development and defense. Similarly, tomato miRNAs putatively targeting M. incognita biological processes have negative effects on digestion, mobility, and reproduction. To experimentally test this hypothesis, an in vitro feeding assay was carried out using sly-miRNAs selected from the bioinformatics approach. The results show that two tomato miRNAs (sly-miRNA156a, sly-miR169f) soaked by juvenile larvae (J2s) affected their ability to infect plant roots and form galls. This was also coupled with a significant downregulation of predicted target genes (Minc11367, Minc00111), as revealed by a qRT-PCR analysis. Discussions Therefore, the current study expands the knowledge related to the cross-kingdom miRNAs involvement in host-parasite interactions and could pave the way for the application of exogenous plant miRNAs as tools to control nematode infection.
Collapse
Affiliation(s)
- Paola Leonetti
- Institute for Sustainable Plant Protection of the National Research Council, Unit of Bari, Bari, Italy
| | - Debora Dallera
- Laboratory of Bioinformatics, Mathematical Modelling, and Synthetic Biology, Department of Electrical, Computer and Biomedical Engineering - Centre for Health Technology, University of Pavia, Pavia, Italy
| | - Davide De Marchi
- Laboratory of Bioinformatics, Mathematical Modelling, and Synthetic Biology, Department of Electrical, Computer and Biomedical Engineering - Centre for Health Technology, University of Pavia, Pavia, Italy
| | - Pamela Candito
- Laboratory of Bioinformatics, Mathematical Modelling, and Synthetic Biology, Department of Electrical, Computer and Biomedical Engineering - Centre for Health Technology, University of Pavia, Pavia, Italy
| | - Lorenzo Pasotti
- Laboratory of Bioinformatics, Mathematical Modelling, and Synthetic Biology, Department of Electrical, Computer and Biomedical Engineering - Centre for Health Technology, University of Pavia, Pavia, Italy
| | - Anca Macovei
- Plant Biotechnology Laboratory, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, Pavia, Italy
| |
Collapse
|
17
|
Mignerot L, Gimond C, Bolelli L, Bouleau C, Sandjak A, Boulin T, Braendle C. Natural variation in the Caenorhabditis elegans egg-laying circuit modulates an intergenerational fitness trade-off. eLife 2024; 12:RP88253. [PMID: 38564369 PMCID: PMC10987095 DOI: 10.7554/elife.88253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024] Open
Abstract
Evolutionary transitions from egg laying (oviparity) to live birth (viviparity) are common across various taxa. Many species also exhibit genetic variation in egg-laying mode or display an intermediate mode with laid eggs containing embryos at various stages of development. Understanding the mechanistic basis and fitness consequences of such variation remains experimentally challenging. Here, we report highly variable intra-uterine egg retention across 316 Caenorhabditis elegans wild strains, some exhibiting strong retention, followed by internal hatching. We identify multiple evolutionary origins of such phenotypic extremes and pinpoint underlying candidate loci. Behavioral analysis and genetic manipulation indicates that this variation arises from genetic differences in the neuromodulatory architecture of the egg-laying circuitry. We provide experimental evidence that while strong egg retention can decrease maternal fitness due to in utero hatching, it may enhance offspring protection and confer a competitive advantage. Therefore, natural variation in C. elegans egg-laying behaviour can alter an apparent trade-off between different fitness components across generations. Our findings highlight underappreciated diversity in C. elegans egg-laying behavior and shed light on its fitness consequences. This behavioral variation offers a promising model to elucidate the molecular changes in a simple neural circuit underlying evolutionary shifts between alternative egg-laying modes in invertebrates.
Collapse
Affiliation(s)
| | | | | | | | - Asma Sandjak
- Université Côte d’Azur, CNRS, Inserm, IBVNiceFrance
| | - Thomas Boulin
- Institut NeuroMyoGène, CNRS, Inserm, Université de LyonLyonFrance
| | | |
Collapse
|
18
|
Riboul DV, Crill S, Oliva CD, Restifo MG, Joseph R, Joseph K, Nguyen KC, Hall DH, Fily Y, Macleod GT. Ultrastructural analysis reveals mitochondrial placement independent of synapse placement in fine caliber C. elegans neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.30.542959. [PMID: 37398149 PMCID: PMC10312582 DOI: 10.1101/2023.05.30.542959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Neurons rely on mitochondria for an efficient supply of ATP and other metabolites. However, while neurons are highly elongated, mitochondria are discrete and limited in number. Due to the slow rates of diffusion over long distances it follows that neurons would benefit from an ability to control the distribution of mitochondria to sites of high metabolic activity, such as synapses. It is assumed that neurons' possess this capacity, but ultrastructural data over substantial portions of a neuron's extent that would allow for tests of such hypotheses are scarce. Here, we mined the Caenorhabditis elegans electron micrographs of John White and Sydney Brenner and found systematic differences in average mitochondrial length (ranging from 1.3 to 2.4 μm), volume density (3.7% to 6.5%) and diameter (0.18 to 0.24 μm) between neurons of different neurotransmitter type and function, but found limited differences in mitochondrial morphometrics between axons and dendrites of the same neurons. Analyses of distance intervals found mitochondria to be distributed randomly with respect to presynaptic specializations, and an indication that mitochondria were displaced from postsynaptic specializations. Presynaptic specializations were primarily localized to varicosities, but mitochondria were no more likely to be found in synaptic varicosities than non-synaptic varicosities. Consistently, mitochondrial volume density was no greater in varicosities with synapses. Therefore, beyond the capacity to disperse mitochondria throughout their length, at least in C. elegans, fine caliber neurons manifest limited sub-cellular control of mitochondrial size and distribution.
Collapse
|
19
|
Roggenbuck EC, Hall EA, Hanson IB, Roby AA, Zhang KK, Alkatib KA, Carter JA, Clewner JE, Gelfius AL, Gong S, Gordon FR, Iseler JN, Kotapati S, Li M, Maysun A, McCormick EO, Rastogi G, Sengupta S, Uzoma CU, Wolkov MA, Clowney EJ. Let's talk about sex: Mechanisms of neural sexual differentiation in Bilateria. WIREs Mech Dis 2024; 16:e1636. [PMID: 38185860 DOI: 10.1002/wsbm.1636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 01/09/2024]
Abstract
In multicellular organisms, sexed gonads have evolved that facilitate release of sperm versus eggs, and bilaterian animals purposefully combine their gametes via mating behaviors. Distinct neural circuits have evolved that control these physically different mating events for animals producing eggs from ovaries versus sperm from testis. In this review, we will describe the developmental mechanisms that sexually differentiate neural circuits across three major clades of bilaterian animals-Ecdysozoa, Deuterosomia, and Lophotrochozoa. While many of the mechanisms inducing somatic and neuronal sex differentiation across these diverse organisms are clade-specific rather than evolutionarily conserved, we develop a common framework for considering the developmental logic of these events and the types of neuronal differences that produce sex-differentiated behaviors. This article is categorized under: Congenital Diseases > Stem Cells and Development Neurological Diseases > Stem Cells and Development.
Collapse
Affiliation(s)
- Emma C Roggenbuck
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elijah A Hall
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Isabel B Hanson
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Alyssa A Roby
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine K Zhang
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Kyle A Alkatib
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Joseph A Carter
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jarred E Clewner
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Anna L Gelfius
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Shiyuan Gong
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Finley R Gordon
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jolene N Iseler
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Samhita Kotapati
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Marilyn Li
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Areeba Maysun
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elise O McCormick
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Geetanjali Rastogi
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Srijani Sengupta
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Chantal U Uzoma
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Madison A Wolkov
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - E Josephine Clowney
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Michigan Neuroscience Institute Affiliate, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
20
|
Li R, Xu Y, Wen X, Chen YH, Wang PZ, Zhao JL, Wu PP, Wu JJ, Liu H, Huang JH, Li SJ, Wu ZX. GCY-20 signaling controls suppression of Caenorhabditis elegans egg laying by moderate cold. Cell Rep 2024; 43:113708. [PMID: 38294902 DOI: 10.1016/j.celrep.2024.113708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/19/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Organisms sensing environmental cues and internal states and integrating the sensory information to control fecundity are essential for survival and proliferation. The present study finds that a moderate cold temperature of 11°C reduces egg laying in Caenorhabditis elegans. ASEL and AWC neurons sense the cold via GCY-20 signaling and act antagonistically on egg laying through the ASEL and AWC/AIA/HSN circuits. Upon cold stimulation, ASEL and AWC release glutamate to activate and inhibit AIA interneurons by acting on highly and lowly sensitive ionotropic GLR-2 and GLC-3 receptors, respectively. AIA inhibits HSN motor neuron activity via acetylcholinergic ACR-14 receptor signaling and suppresses egg laying. Thus, ASEL and AWC initiate and reduce the cold suppression of egg laying. ASEL's action on AIA and egg laying dominates AWC's action. The biased opposite actions of these neurons on egg laying provide animals with a precise adaptation of reproductive behavior to environmental temperatures.
Collapse
Affiliation(s)
- Rong Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Xu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Wen
- College of Life Science, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yuan-Hua Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Ping-Zhou Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jia-Lu Zhao
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Piao-Ping Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jing-Jing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jia-Hao Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Si-Jia Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zheng-Xing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
21
|
Jose A, Collins K. NALCN Channels Are Not Major targets of Gα o or Gα q Modulation in the C. elegans Egg-Laying Behavior Circuit. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001065. [PMID: 38287929 PMCID: PMC10823792 DOI: 10.17912/micropub.biology.001065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 01/31/2024]
Abstract
Sodium leak channels (NALCN) are regulators of cell membrane potential. Previous studies in mammalian neurons and C. elegans have shown that Gα q and Gα o signaling antagonistically modulates NALCN activity to regulate neuron excitability and neurotransmitter release for behavior. Here, we test whether NALCNs mediate the effects of Gα q and/or Gα o signaling in the C. elegans egg-laying circuit. We find that while gain-of-function NALCN mutants exhibit hyperactive egg-laying behavior, NALCNs are not required for the effects of Gα q or Gα o signaling for egg laying. These results show that NALCNs are not major effectors of G-protein signaling for C. elegans egg-laying behavior.
Collapse
Affiliation(s)
- Ariana Jose
- Physiology & Biophysics, University of Miami, Coral Gables, Florida, United States
| | - Kevin Collins
- Biology, University of Miami, Coral Gables, Florida, United States
| |
Collapse
|
22
|
McDonald NA, Tao L, Dong MQ, Shen K. SAD-1 kinase controls presynaptic phase separation by relieving SYD-2/Liprin-α autoinhibition. PLoS Biol 2023; 21:e3002421. [PMID: 38048304 PMCID: PMC10695385 DOI: 10.1371/journal.pbio.3002421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/06/2023] [Indexed: 12/06/2023] Open
Abstract
Neuronal development orchestrates the formation of an enormous number of synapses that connect the nervous system. In developing presynapses, the core active zone structure has been found to assemble through liquid-liquid phase separation. Here, we find that the phase separation of Caenorhabditis elegans SYD-2/Liprin-α, a key active zone scaffold, is controlled by phosphorylation. We identify the SAD-1 kinase as a regulator of SYD-2 phase separation and determine presynaptic assembly is impaired in sad-1 mutants and increased by overactivation of SAD-1. Using phosphoproteomics, we find SAD-1 phosphorylates SYD-2 on 3 sites that are critical to activate phase separation. Mechanistically, SAD-1 phosphorylation relieves a binding interaction between 2 folded domains in SYD-2 that inhibits phase separation by an intrinsically disordered region (IDR). We find synaptic cell adhesion molecules localize SAD-1 to nascent synapses upstream of active zone formation. We conclude that SAD-1 phosphorylates SYD-2 at developing synapses, activating its phase separation and active zone assembly.
Collapse
Affiliation(s)
- Nathan A. McDonald
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Li Tao
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, People’s Republic of China
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Stanford University, Stanford, California, United States of America
| |
Collapse
|
23
|
Prakash SJ, Van Auken KM, Hill DP, Sternberg PW. Semantic representation of neural circuit knowledge in Caenorhabditis elegans. Brain Inform 2023; 10:30. [PMID: 37947958 PMCID: PMC10638142 DOI: 10.1186/s40708-023-00208-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/22/2023] [Indexed: 11/12/2023] Open
Abstract
In modern biology, new knowledge is generated quickly, making it challenging for researchers to efficiently acquire and synthesise new information from the large volume of primary publications. To address this problem, computational approaches that generate machine-readable representations of scientific findings in the form of knowledge graphs have been developed. These representations can integrate different types of experimental data from multiple papers and biological knowledge bases in a unifying data model, providing a complementary method to manual review for interacting with published knowledge. The Gene Ontology Consortium (GOC) has created a semantic modelling framework that extends individual functional gene annotations to structured descriptions of causal networks representing biological processes (Gene Ontology-Causal Activity Modelling, or GO-CAM). In this study, we explored whether the GO-CAM framework could represent knowledge of the causal relationships between environmental inputs, neural circuits and behavior in the model nematode C. elegans [C. elegans Neural-Circuit Causal Activity Modelling (CeN-CAM)]. We found that, given extensions to several relevant ontologies, a wide variety of author statements from the literature about the neural circuit basis of egg-laying and carbon dioxide (CO2) avoidance behaviors could be faithfully represented with CeN-CAM. Through this process, we were able to generate generic data models for several categories of experimental results. We also discuss how semantic modelling may be used to functionally annotate the C. elegans connectome. Thus, Gene Ontology-based semantic modelling has the potential to support various machine-readable representations of neurobiological knowledge.
Collapse
Affiliation(s)
- Sharan J Prakash
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Kimberly M Van Auken
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - David P Hill
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
| |
Collapse
|
24
|
Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Meng B, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. Curr Biol 2023; 33:4430-4445.e6. [PMID: 37769660 PMCID: PMC10860333 DOI: 10.1016/j.cub.2023.08.088] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/24/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior.
Collapse
Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Casey M Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bohan Meng
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexandra B Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
25
|
Silva AC, Dos Santos AGR, Pieretti JC, Rolim WR, Seabra AB, Ávila DS. Iron oxide/silver hybrid nanoparticles impair the cholinergic system and cause reprotoxicity in Caenorhabditis elegans. Food Chem Toxicol 2023; 179:113945. [PMID: 37451599 DOI: 10.1016/j.fct.2023.113945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/27/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Iron oxide nanoparticles present superparamagnetic properties that enable their application in various areas, including drug delivery at specific locations in the organism. Silver nanoparticles have potent antimicrobial effects. Although the combination of Fe3O4-NPs and Ag-NPs in one hybrid nanostructure (Fe3O4@Ag-NPs) demonstrated promising targeted biomedical applications, their toxicological effects are unknown and need to be assessed. Caenorhabditis elegans is a promising model for nanotoxicological analysis, as it allows an initial screening of new substances. After exposure to Fe3O4-NPs, Ag-NPs and Fe3O4@Ag-NPs, we observed that hybrid NPs reduced the C. elegans survival and reproduction. Higher concentrations of Fe3O4@Ag-NPs caused an increase in cell apoptosis in the germline and a decrease in egg laying, which was associated with a decrease in worm swimming movements and abnormalities in the cholinergic neurons. Fe3O4@Ag-NPs caused an increase in reactive oxygen species, along with activation of DAF-16 transcription factor. A higher expression of the target genes GST-4::GFP and SOD-3::GFP were evidenced, which suggests the activation of the antioxidant system. Our results indicate the reprotoxicity caused by high levels of Fe3O4@Ag-NPs, as well as cholinergic neurotoxicity and activation of the antioxidant system in C. elegans, suggesting that high concentrations of these nanomaterials can be harmful to living organisms.
Collapse
Affiliation(s)
- Aline Castro Silva
- Graduate Program in Biochemistry, Laboratory of Biochemistry and Toxicology in Caenorhabditis Elegans, Federal University of Pampa, Uruguaiana, RS, Zip code 97500-970, Brazil
| | - Alisson Gleysson Rodrigues Dos Santos
- Graduate Program in Biochemistry, Laboratory of Biochemistry and Toxicology in Caenorhabditis Elegans, Federal University of Pampa, Uruguaiana, RS, Zip code 97500-970, Brazil
| | - Joana Claudio Pieretti
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), Santo André, SP, Zip code 09210-580, Brazil
| | - Wallace Rosado Rolim
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), Santo André, SP, Zip code 09210-580, Brazil
| | - Amedea Barozzi Seabra
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), Santo André, SP, Zip code 09210-580, Brazil
| | - Daiana Silva Ávila
- Graduate Program in Biochemistry, Laboratory of Biochemistry and Toxicology in Caenorhabditis Elegans, Federal University of Pampa, Uruguaiana, RS, Zip code 97500-970, Brazil.
| |
Collapse
|
26
|
Almoril-Porras A, Calvo AC, Niu L, Beagan J, Hawk JD, Aljobeh A, Wisdom EM, Ren I, Díaz-García M, Wang ZW, Colón-Ramos DA. Specific configurations of electrical synapses filter sensory information to drive choices in behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551556. [PMID: 37577611 PMCID: PMC10418224 DOI: 10.1101/2023.08.01.551556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Synaptic configurations in precisely wired circuits underpin how sensory information is processed by the nervous system, and the emerging animal behavior. This is best understood for chemical synapses, but far less is known about how electrical synaptic configurations modulate, in vivo and in specific neurons, sensory information processing and context-specific behaviors. We discovered that INX-1, a gap junction protein that forms electrical synapses, is required to deploy context-specific behavioral strategies during C. elegans thermotaxis behavior. INX-1 couples two bilaterally symmetric interneurons, and this configuration is required for the integration of sensory information during migration of animals across temperature gradients. In inx-1 mutants, uncoupled interneurons display increased excitability and responses to subthreshold temperature stimuli, resulting in abnormally longer run durations and context-irrelevant tracking of isotherms. Our study uncovers a conserved configuration of electrical synapses that, by increasing neuronal capacitance, enables differential processing of sensory information and the deployment of context-specific behavioral strategies.
Collapse
Affiliation(s)
- Agustin Almoril-Porras
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ana C. Calvo
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Longgang Niu
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Jonathan Beagan
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Josh D. Hawk
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ahmad Aljobeh
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Elias M. Wisdom
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ivy Ren
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Malcom Díaz-García
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Daniel A. Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
- Wu Tsai Institute, Yale University; New Haven, CT 06510, USA
- Marine Biological Laboratory; Woods Hole, MA, USA
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico; San Juan 00901, Puerto Rico
| |
Collapse
|
27
|
McDonald NA, Tao L, Dong MQ, Shen K. SAD-1 kinase controls presynaptic phase separation by relieving SYD-2/Liprin-α autoinhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544643. [PMID: 37398223 PMCID: PMC10312667 DOI: 10.1101/2023.06.12.544643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Neuronal development orchestrates the formation of an enormous number of synapses that connect the nervous system. In developing presynapses, the core active zone structure has been found to assemble through a liquid-liquid phase separation. Here, we find that the phase separation of SYD-2/Liprin-α, a key active zone scaffold, is controlled by phosphorylation. Using phosphoproteomics, we identify the SAD-1 kinase to phosphorylate SYD-2 and a number of other substrates. Presynaptic assembly is impaired in sad-1 mutants and increased by overactivation of SAD-1. We determine SAD-1 phosphorylation of SYD-2 at three sites is critical to activate its phase separation. Mechanistically, phosphorylation relieves a binding interaction between two folded SYD-2 domains that inhibits phase separation by an intrinsically disordered region. We find synaptic cell adhesion molecules localize SAD-1 to nascent synapses upstream of active zone formation. We conclude that SAD-1 phosphorylates SYD-2 at developing synapses, enabling its phase separation and active zone assembly.
Collapse
Affiliation(s)
| | - Li Tao
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| |
Collapse
|
28
|
Medrano E, Collins KM. Muscle-directed mechanosensory feedback activates egg-laying circuit activity and behavior in Caenorhabditis elegans. Curr Biol 2023; 33:2330-2339.e8. [PMID: 37236183 PMCID: PMC10280788 DOI: 10.1016/j.cub.2023.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 03/29/2023] [Accepted: 05/03/2023] [Indexed: 05/28/2023]
Abstract
Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce.1 For instance, stretch in the Drosophila reproductive tract produced by artificial distention or from accumulated eggs regulates the attraction to acetic acid to ensure optimal oviposition.2 How such mechanosensory feedback modulates neural circuits to coordinate reproductive behaviors is incompletely understood. We previously identified a stretch-dependent homeostat that regulates egg laying in Caenorhabditis elegans. Sterilized animals lacking eggs show reduced Ca2+ transient activity in the presynaptic HSN command motoneurons that drive egg-laying behavior, while animals forced to accumulate extra eggs show dramatically increased circuit activity that restores egg laying.3 Interestingly, genetic ablation or electrical silencing of the HSNs delays, but does not abolish, the onset of egg laying,3,4,5 with animals recovering vulval muscle Ca2+ transient activity upon egg accumulation.6 Using an acute gonad microinjection technique to mimic changes in pressure and stretch resulting from germline activity and egg accumulation, we find that injection rapidly stimulates Ca2+ activity in both neurons and muscles of the egg-laying circuit. Injection-induced vulval muscle Ca2+ activity requires L-type Ca2+ channels but is independent of presynaptic input. Conversely, injection-induced neural activity is disrupted in mutants lacking the vulval muscles, suggesting "bottom-up" feedback from muscles to neurons. Direct mechanical prodding activates the vulval muscles, suggesting that they are the proximal targets of the stretch-dependent stimulus. Our results show that egg-laying behavior in C. elegans is regulated by a stretch-dependent homeostat that scales postsynaptic muscle responses with egg accumulation in the uterus.
Collapse
Affiliation(s)
- Emmanuel Medrano
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | - Kevin M Collins
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA.
| |
Collapse
|
29
|
Olson AC, Butt AM, Christie NTM, Shelar A, Koelle MR. Multiple Subthreshold GPCR Signals Combined by the G-Proteins Gα q and Gα s Activate the Caenorhabditis elegans Egg-Laying Muscles. J Neurosci 2023; 43:3789-3806. [PMID: 37055179 PMCID: PMC10219013 DOI: 10.1523/jneurosci.2301-22.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/21/2023] [Accepted: 04/07/2023] [Indexed: 04/15/2023] Open
Abstract
Individual neurons or muscle cells express many G-protein-coupled receptors (GPCRs) for neurotransmitters and neuropeptides, yet it remains unclear how cells integrate multiple GPCR signals that all must activate the same few G-proteins. We analyzed this issue in the Caenorhabditis elegans egg-laying system, where multiple GPCRs on muscle cells promote contraction and egg laying. We genetically manipulated individual GPCRs and G-proteins specifically in these muscle cells within intact animals and then measured egg laying and muscle calcium activity. Two serotonin GPCRs on the muscle cells, Gαq-coupled SER-1 and Gαs-coupled SER-7, together promote egg laying in response to serotonin. We found that signals produced by either SER-1/Gαq or SER-7/Gαs alone have little effect, but these two subthreshold signals combine to activate egg laying. We then transgenically expressed natural or designer GPCRs in the muscle cells and found that their subthreshold signals can also combine to induce muscle activity. However, artificially inducing strong signaling through just one of these GPCRs can be sufficient to induce egg laying. Knocking down Gαq and Gαs in the egg-laying muscle cells induced egg-laying defects that were stronger than those of a SER-1/SER-7 double knockout, indicating that additional endogenous GPCRs also activate the muscle cells. These results show that in the egg-laying muscles multiple GPCRs for serotonin and other signals each produce weak effects that individually do not result in strong behavioral outcomes. However, they combine to produce sufficient levels of Gαq and Gαs signaling to promote muscle activity and egg laying.SIGNIFICANCE STATEMENT How can neurons and other cells gather multiple independent pieces of information from the soup of chemical signals in their environment and compute an appropriate response? Most cells express >20 GPCRs that each receive one signal and transmit that information through three main types of G-proteins. We analyzed how this machinery generates responses by studying the egg-laying system of C. elegans, where serotonin and multiple other signals act through GPCRs on the egg-laying muscles to promote muscle activity and egg laying. We found that individual GPCRs within an intact animal each generate effects too weak to activate egg laying. However, combined signaling from multiple GPCR types reaches a threshold capable of activating the muscle cells.
Collapse
Affiliation(s)
- Andrew C Olson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Allison M Butt
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Nakeirah T M Christie
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Ashish Shelar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| |
Collapse
|
30
|
Porta-de-la-Riva M, Gonzalez AC, Sanfeliu-Cerdán N, Karimi S, Malaiwong N, Pidde A, Morales-Curiel LF, Fernandez P, González-Bolívar S, Hurth C, Krieg M. Neural engineering with photons as synaptic transmitters. Nat Methods 2023; 20:761-769. [PMID: 37024651 DOI: 10.1038/s41592-023-01836-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 03/03/2023] [Indexed: 04/08/2023]
Abstract
Neuronal computation is achieved through connections of individual neurons into a larger network. To expand the repertoire of endogenous cellular communication, we developed a synthetic, photon-assisted synaptic transmission (PhAST) system. PhAST is based on luciferases and channelrhodopsins that enable the transmission of a neuronal state across space, using photons as neurotransmitters. PhAST overcomes synaptic barriers and rescues the behavioral deficit of a glutamate mutant with conditional, calcium-triggered photon emission between two neurons of the Caenorhabditis elegans nociceptive avoidance circuit. To demonstrate versatility and flexibility, we generated de novo synaptic transmission between two unconnected cells in a sexually dimorphic neuronal circuit, suppressed endogenous nocifensive response through activation of an anion channelrhodopsin and switched attractive to aversive behavior in an olfactory circuit. Finally, we applied PhAST to dissect the calcium dynamics of the temporal pattern generator in a motor circuit for ovipositioning. In summary, we established photon-based synaptic transmission that facilitates the modification of animal behavior.
Collapse
Affiliation(s)
| | | | | | - Shadi Karimi
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | | | | | | | | | | | - Cedric Hurth
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | - Michael Krieg
- Institut de Ciències Fotòniques, Castelldefels, Spain.
| |
Collapse
|
31
|
Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.02.532814. [PMID: 37034579 PMCID: PMC10081309 DOI: 10.1101/2023.04.02.532814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neuron classes in the circuits that generate behavior have a remarkable capacity for flexibility, as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of highly coordinated behaviors remains unknown. Here we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg-laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg-laying and locomotion while also biasing the animals towards low-speed dwelling behavior over longer timescales. The acute effects of HSN on egg-laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal projections. The long-lasting effects on dwelling are mediated by HSN release of serotonin that is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal for the first time that neurons can borrow serotonin from one another to control behavior.
Collapse
Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Casey M. Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew A. Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alexandra B. Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Steven W. Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
32
|
Mechanosensitive body–brain interactions in Caenorhabditis elegans. Curr Opin Neurobiol 2022; 75:102574. [DOI: 10.1016/j.conb.2022.102574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 12/13/2022]
|
33
|
Dhakal P, Chaudhry SI, Signorelli R, Collins KM. Serotonin signals through postsynaptic Gαq, Trio RhoGEF, and diacylglycerol to promote Caenorhabditis elegans egg-laying circuit activity and behavior. Genetics 2022; 221:iyac084. [PMID: 35579369 PMCID: PMC9252285 DOI: 10.1093/genetics/iyac084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/26/2022] [Indexed: 11/12/2022] Open
Abstract
Activated Gαq signals through phospholipase-Cβ and Trio, a Rho GTPase exchange factor (RhoGEF), but how these distinct effector pathways promote cellular responses to neurotransmitters like serotonin remains poorly understood. We used the egg-laying behavior circuit of Caenorhabditis elegans to determine whether phospholipase-Cβ and Trio mediate serotonin and Gαq signaling through independent or related biochemical pathways. Our genetic rescue experiments suggest that phospholipase-Cβ functions in neurons while Trio Rho GTPase exchange factor functions in both neurons and the postsynaptic vulval muscles. While Gαq, phospholipase-Cβ, and Trio Rho GTPase exchange factor mutants fail to lay eggs in response to serotonin, optogenetic stimulation of the serotonin-releasing HSN neurons restores egg laying only in phospholipase-Cβ mutants. Phospholipase-Cβ mutants showed vulval muscle Ca2+ transients while strong Gαq and Trio Rho GTPase exchange factor mutants had little or no vulval muscle Ca2+ activity. Treatment with phorbol 12-myristate 13-acetate that mimics 1,2-diacylglycerol, a product of PIP2 hydrolysis, rescued egg-laying circuit activity and behavior defects of Gαq signaling mutants, suggesting both phospholipase-C and Rho signaling promote synaptic transmission and egg laying via modulation of 1,2-diacylglycerol levels. 1,2-Diacylglycerol activates effectors including UNC-13; however, we find that phorbol esters, but not serotonin, stimulate egg laying in unc-13 and phospholipase-Cβ mutants. These results support a model where serotonin signaling through Gαq, phospholipase-Cβ, and UNC-13 promotes neurotransmitter release, and that serotonin also signals through Gαq, Trio Rho GTPase exchange factor, and an unidentified, phorbol 12-myristate 13-acetate-responsive effector to promote postsynaptic muscle excitability. Thus, the same neuromodulator serotonin can signal in distinct cells and effector pathways to coordinate activation of a motor behavior circuit.
Collapse
Affiliation(s)
- Pravat Dhakal
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | - Sana I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | | | - Kevin M Collins
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| |
Collapse
|
34
|
Yang S, Park D, Manning L, Hill SE, Cao M, Xuan Z, Gonzalez I, Dong Y, Clark B, Shao L, Okeke I, Almoril-Porras A, Bai J, De Camilli P, Colón-Ramos DA. Presynaptic autophagy is coupled to the synaptic vesicle cycle via ATG-9. Neuron 2022; 110:824-840.e10. [PMID: 35065714 PMCID: PMC9017068 DOI: 10.1016/j.neuron.2021.12.031] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 10/20/2021] [Accepted: 12/20/2021] [Indexed: 01/01/2023]
Abstract
Autophagy is a cellular degradation pathway essential for neuronal health and function. Autophagosome biogenesis occurs at synapses, is locally regulated, and increases in response to neuronal activity. The mechanisms that couple autophagosome biogenesis to synaptic activity remain unknown. In this study, we determine that trafficking of ATG-9, the only transmembrane protein in the core autophagy pathway, links the synaptic vesicle cycle with autophagy. ATG-9-positive vesicles in C. elegans are generated from the trans-Golgi network via AP-3-dependent budding and delivered to presynaptic sites. At presynaptic sites, ATG-9 undergoes exo-endocytosis in an activity-dependent manner. Mutations that disrupt endocytosis, including a lesion in synaptojanin 1 associated with Parkinson's disease, result in abnormal ATG-9 accumulation at clathrin-rich synaptic foci and defects in activity-induced presynaptic autophagy. Our findings uncover regulated key steps of ATG-9 trafficking at presynaptic sites and provide evidence that ATG-9 exo-endocytosis couples autophagosome biogenesis at presynaptic sites with the activity-dependent synaptic vesicle cycle.
Collapse
Affiliation(s)
- Sisi Yang
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Daehun Park
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Laura Manning
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Sarah E Hill
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Mian Cao
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Zhao Xuan
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Ian Gonzalez
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Yongming Dong
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Benjamin Clark
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Lin Shao
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Ifechukwu Okeke
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Agustin Almoril-Porras
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA
| | - Jihong Bai
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Pietro De Camilli
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Daniel A Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, 260 Whitney Avenue, YSB C167, New Haven, CT 06511, USA; Instituto de Neurobiología José del Castillo, Recinto de Ciencias Médicas, Universidad de Puerto Rico, 201 Boulevard del Valle, San Juan, PR 00901, USA; Wu Tsai Institute, Yale University, New Haven, CT 06510, USA.
| |
Collapse
|
35
|
Zhang B, Lam KY, Ni WM, Signorelli R, Collins KM, Fu Z, Zhai L, Lou Y, DeAngelis DL, Hastings A. Directed movement changes coexistence outcomes in heterogeneous environments. Ecol Lett 2022; 25:366-377. [PMID: 34818698 PMCID: PMC8799502 DOI: 10.1111/ele.13925] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/11/2021] [Accepted: 10/27/2021] [Indexed: 02/03/2023]
Abstract
Understanding mechanisms of coexistence is a central topic in ecology. Mathematical analysis of models of competition between two identical species moving at different rates of symmetric diffusion in heterogeneous environments show that the slower mover excludes the faster one. The models have not been tested empirically and lack inclusions of a component of directed movement toward favourable areas. To address these gaps, we extended previous theory by explicitly including exploitable resource dynamics and directed movement. We tested the mathematical results experimentally using laboratory populations of the nematode worm, Caenorhabditis elegans. Our results not only support the previous theory that the species diffusing at a slower rate prevails in heterogeneous environments but also reveal that moderate levels of a directed movement component on top of the diffusive movement allow species to coexist. Our results broaden the theory of species coexistence in heterogeneous space and provide empirical confirmation of the mathematical predictions.
Collapse
Affiliation(s)
- Bo Zhang
- Department of Integrative Biology, Oklahoma State University, United States
| | - King-Yeung Lam
- Department of Mathematics, Ohio State University, United States
| | - Wei-Ming Ni
- Chinese University of Hong Kong – Shenzhen, China
| | | | | | - Zhiyuan Fu
- Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University, China
| | - Lu Zhai
- Department of Natural Ecology Resource and Management, Oklahoma State University, United States
| | - Yuan Lou
- Department of Mathematics, Ohio State University, United States
| | | | - Alan Hastings
- Department of Environmental Science and Policy, University of California, Davis, United States; Santa Fe Institute, United States
| |
Collapse
|
36
|
Barmaver SN, Muthaiyan Shanmugam M, Wagner OI. Methods to Quantify and Relate Axonal Transport Defects to Changes in C. elegans Behavior. Methods Mol Biol 2022; 2431:481-497. [PMID: 35412294 DOI: 10.1007/978-1-0716-1990-2_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Neuronal growth, differentiation, homeostasis, viability, and injury response heavily rely on functional axonal transport (AT). Erroneous and disturbed AT may lead to accumulation of "disease proteins" such as tau, α-synuclein, or amyloid precursor protein causing various neurological disorders. Changes in AT often lead to observable behavioral consequences in C. elegans such as impeded movements, defects in touch response, chemosensation, and even egg laying. Long C. elegans neurons with clear distinguishable axons and dendrites provide an excellent platform to analyze AT. The possibility to relate changes in AT to neuronal defects that in turn lead to quantifiable changes in worm behavior allows for the advancement of neuropathological disease models. Even more, subsequent suppressor screens may aid in identifying genes responsible for observed behavioral changes providing a target for drug development to eventually delay or cure neurological diseases. Thus, in this chapter, we summarize critical methods to identify and quantify defects in axonal transport as well as exemplified behavioral assays that may relate to these defects.
Collapse
Affiliation(s)
- Syed Nooruzuha Barmaver
- Department of Life Science, Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Muniesh Muthaiyan Shanmugam
- Department of Life Science, Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Oliver Ingvar Wagner
- Department of Life Science, Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.
| |
Collapse
|
37
|
Effects of essential oil components exposure on biological parameters of Caenorhabditis elegans. Food Chem Toxicol 2021; 159:112763. [PMID: 34896182 DOI: 10.1016/j.fct.2021.112763] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/03/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022]
Abstract
The extensive use of essential oil components in an increasing number of applications can substantially enhance exposure to these compounds, which leads to potential health and environmental hazards. This work aimed to evaluate the toxicity of four widely used essential oil components (carvacrol, eugenol, thymol, vanillin) using the in vivo model Caenorhabditis elegans. For this purpose, the LC50 value of acute exposure to these components was first established; then the effect of sublethal concentrations on nematodes' locomotion behaviour, reproduction, heat and oxidative stress resistance and chemotaxis was evaluated. The results showed that all the components had a concentration-dependent effect on nematode survival at moderate to high concentrations. Carvacrol and thymol were the two most toxic compounds, while vanillin had the mildest toxicological effect. Reproduction resulted in a more sensitive endpoint than lethality to evaluate toxicity. Only pre-exposure to carvacrol and eugenol at the highest tested sublethal concentrations conferred worms oxidative stress resistance. However, at these and lower concentrations, both components induced reproductive toxicity. Our results evidence that these compounds can be toxic at lower doses than those required for their biological action. These findings highlight the need for a specific toxicological assessment of every EOC application.
Collapse
|
38
|
Muthubharathi BC, Balasubramaniam B, Mir DA, Ravichandiran V, Balamurugan K. Physiological and Metabolite Alterations Associated with Neuronal Signals of Caenorhabditis elegans during Cronobacter sakazakii Infections. ACS Chem Neurosci 2021; 12:4336-4349. [PMID: 34704733 DOI: 10.1021/acschemneuro.1c00559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Metabolomic reprogramming plays a crucial role in the activation of several regulatory mechanisms including neuronal responses of the host. In the present study, alterations at physiological and biochemical levels were initially assessed to monitor the impact of the candidate pathogen Cronobacter sakazakii on the nematode host Caenorhabditis elegans. The abnormal behavioral responses were observed in infected worms in terms of hyperosmolarity and high viscous chemicals. The microscopic observations indicated reduction in egg laying and internal hatching of larvae in the host. An increased level of total reactive oxygen species and reduction in antioxidant agents such as glutathione and catalase were observed. These observations suggested the severe effect of C. sakazakii infection on C. elegans. To understand the small molecules which likely mediated neurotransmission, the whole metabolome of C. elegans during the infection of C. sakazakii was analyzed using liquid chromatography-mass spectrometry. A decrease in the quantity of methyl dopamine and palmitoyl dopamine and an increase in hydroxyl dopamine suggested that reduction in dopamine reuptake and dopamine neuronal stress. The disordered dopaminergic transmission during infection was confirmed using transgenic C. elegans by microscopic observation of Dat-1 protein expression. In addition, reduction in arachidonic acid and short-chain fatty acids revealed their effect on lipid droplet formation as well as neuronal damage. An increase in the quantity of stearoyl CoA underpinned the higher accumulation of lipid droplets in the host. On the other hand, an increased level of metabolites such as palmitoyl serotonin, citalopram N-oxide, and N-acyl palmitoyl serotonin revealed serotonin-mediated potential response for neuroprotection, cytotoxicity, and cellular damage. Based on the metabolomic data, the genes correspond to small molecules involved in biosynthesis and transportation of candidate neurotransmitters were validated through relative gene expression.
Collapse
Affiliation(s)
| | | | - Dilawar Ahmad Mir
- Department of Biotechnology, Science Campus, Alagappa University, Karaikudi 630003, India
| | | | | |
Collapse
|
39
|
Goodwin SF, Hobert O. Molecular Mechanisms of Sexually Dimorphic Nervous System Patterning in Flies and Worms. Annu Rev Cell Dev Biol 2021; 37:519-547. [PMID: 34613817 DOI: 10.1146/annurev-cellbio-120319-115237] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Male and female brains display anatomical and functional differences. Such differences are observed in species across the animal kingdom, including humans, but have been particularly well-studied in two classic animal model systems, the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans. Here we summarize recent advances in understanding how the worm and fly brain acquire sexually dimorphic features during development. We highlight the advantages of each system, illustrating how the precise anatomical delineation of sexual dimorphisms in worms has enabled recent analysis into how these dimorphisms become specified during development, and how focusing on sexually dimorphic neurons in the fly has enabled an increasingly detailed understanding of sex-specific behaviors.
Collapse
Affiliation(s)
- Stephen F Goodwin
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford OX1 3SR, United Kingdom;
| | - Oliver Hobert
- Department of Biological Sciences and Howard Hughes Medical Institute, Columbia University, New York, NY 10027, USA;
| |
Collapse
|
40
|
Godini R, Handley A, Pocock R. Transcription Factors That Control Behavior-Lessons From C. elegans. Front Neurosci 2021; 15:745376. [PMID: 34646119 PMCID: PMC8503520 DOI: 10.3389/fnins.2021.745376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/02/2021] [Indexed: 11/15/2022] Open
Abstract
Behavior encompasses the physical and chemical response to external and internal stimuli. Neurons, each with their own specific molecular identities, act in concert to perceive and relay these stimuli to drive behavior. Generating behavioral responses requires neurons that have the correct morphological, synaptic, and molecular identities. Transcription factors drive the specific gene expression patterns that define these identities, controlling almost every phenomenon in a cell from development to homeostasis. Therefore, transcription factors play an important role in generating and regulating behavior. Here, we describe the transcription factors, the pathways they regulate, and the neurons that drive chemosensation, mechanosensation, thermosensation, osmolarity sensing, complex, and sex-specific behaviors in the animal model Caenorhabditis elegans. We also discuss the current limitations in our knowledge, particularly our minimal understanding of how transcription factors contribute to the adaptive behavioral responses that are necessary for organismal survival.
Collapse
|
41
|
Li J, Qu M, Wang M, Yue Y, Chen Z, Liu R, Bu Y, Li Y. Reproductive toxicity and underlying mechanisms of di(2-ethylhexyl) phthalate in nematode Caenorhabditis elegans. J Environ Sci (China) 2021; 105:1-10. [PMID: 34130826 DOI: 10.1016/j.jes.2020.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
DEHP (di(2-ethylhexyl) phthalate) is an endocrine disruptor commonly found in plastic products that has been associated with reproduction alterations, but the effect of DEHP on toxicity is still widely unknown. Using DEHP concentrations of 10, 1, and 0.1 mg/L, we showed that DEHP reduced the reproductive capacity of Caenorhabditis elegans after 72 hr. of exposure. DEHP exposure reduced the reproductive capacity in terms of decreased brood sizes, egg hatchability (0.1, 1 and 10 mg/L), and egg-laying rate (1 and 10 mg/L), and increased numbers of fertilized eggs in the uterus (1 and 10 mg/L). DEHP also caused damage to gonad development. DEHP decreased the total number of germline cells, and decreased the relative area of the gonad arm of all exposure groups, with worms in the 1 mg/L DEHP exposure group having the minimum gonad arm area. Additionally, DEHP caused a significant concentration-dependent increase in the expression of unc-86. Autophagy and ROS contributed to the enhancement of DEHP toxicity in reducing reproductive capacity, and glutathione peroxidase and superoxide dismutase were activated as the antioxidant defense in this study. Hence, we found that DEHP has a dual effect on nematodes. Higher concentration (10 mg/L) DEHP can inhibit the expression of autophagy genes (atg-18, atg-7, bec-1, lgg-1 and unc-51), and lower concentrations (0.1 and 1 mg/L) can promote the expression of autophagy genes. Our data highlight the potential environmental risk of DEHP in inducing reproductive toxicity toward the gonad development and reproductive capacity of environmental organisms.
Collapse
Affiliation(s)
- Jingjing Li
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Man Qu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Mei Wang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Ying Yue
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Zhaofang Chen
- State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Ran Liu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Yuanqing Bu
- Nanjing Institute of Environmental Science, Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Yunhui Li
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
| |
Collapse
|
42
|
Ravi B, Zhao J, Chaudhry I, Signorelli R, Bartole M, Kopchock RJ, Guijarro C, Kaplan JM, Kang L, Collins KM. Presynaptic Gαo (GOA-1) signals to depress command neuron excitability and allow stretch-dependent modulation of egg laying in Caenorhabditis elegans. Genetics 2021; 218:6284136. [PMID: 34037773 DOI: 10.1093/genetics/iyab080] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/18/2021] [Indexed: 12/29/2022] Open
Abstract
Egg laying in the nematode worm Caenorhabditis elegans is a two-state behavior modulated by internal and external sensory input. We have previously shown that homeostatic feedback of embryo accumulation in the uterus regulates bursting activity of the serotonergic HSN command neurons that sustains the egg-laying active state. How sensory feedback of egg release signals to terminate the egg-laying active state is less understood. We find that Gαo, a conserved Pertussis Toxin-sensitive G protein, signals within HSN to inhibit egg-laying circuit activity and prevent entry into the active state. Gαo signaling hyperpolarizes HSN, reducing HSN Ca2+ activity and input onto the postsynaptic vulval muscles. Loss of inhibitory Gαo signaling uncouples presynaptic HSN activity from a postsynaptic, stretch-dependent homeostat, causing precocious entry into the egg-laying active state when only a few eggs are present in the uterus. Feedback of vulval opening and egg release activates the uv1 neuroendocrine cells which release NLP-7 neuropeptides which signal to inhibit egg laying through Gαo-independent mechanisms in the HSNs and Gαo-dependent mechanisms in cells other than the HSNs. Thus, neuropeptide and inhibitory Gαo signaling maintains a bi-stable state of electrical excitability that dynamically controls circuit activity in response to both external and internal sensory input to drive a two-state behavior output.
Collapse
Affiliation(s)
- Bhavya Ravi
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | - Jian Zhao
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | - Mattingly Bartole
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | | | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - Lijun Kang
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Kevin M Collins
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| |
Collapse
|
43
|
Youssef K, Archonta D, Kubiseski TJ, Tandon A, Rezai P. Electric egg-laying: a new approach for regulating C. elegans egg-laying behaviour in a microchannel using electric field. LAB ON A CHIP 2021; 21:821-834. [PMID: 33527103 DOI: 10.1039/d0lc00964d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this paper, the novel effect of electric field (EF) on adult C. elegans egg-laying in a microchannel is discovered and correlated with neural and muscular activities. The quantitative effects of worm aging and EF strength, direction, and exposure duration on egg-laying are studied phenotypically using egg-count, body length, head movement, and transient neuronal activity readouts. Electric egg-laying rate increases significantly when worms face the anode and the response is EF-dependent, i.e. stronger (6 V cm-1) and longer EF (40 s) exposure result in a shorter egg laying response duration. Worm aging significantly deteriorates the electric egg-laying behaviour with an 88% decrease in the egg-count from day-1 to day-4 post young-adult stage. Fluorescent imaging of intracellular calcium dynamics in the main parts of the egg-laying neural circuit demonstrates the involvement and sensitivity of the serotonergic hermaphrodite specific neurons (HSNs), vulva muscles, and ventral cord neurons to the EF. HSN mutation also results in a reduced rate of electric egg-laying allowing the use of this technique for cellular screening and mapping of the neural basis of electrosensation in C. elegans. This novel assay can be parallelized and performed in a high-throughput manner for drug and gene screening applications.
Collapse
Affiliation(s)
- Khaled Youssef
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
| | - Daphne Archonta
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
| | | | - Anurag Tandon
- Tanz Centre for Research in Neurodegenerative Diseases, Toronto, Ontario, Canada and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON, Canada.
| |
Collapse
|
44
|
Neural and behavioral control in Caenorhabditis elegans by a yellow-light-activatable caged compound. Proc Natl Acad Sci U S A 2021; 118:2009634118. [PMID: 33542099 DOI: 10.1073/pnas.2009634118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Caenorhabditis elegans is used as a model system to understand the neural basis of behavior, but application of caged compounds to manipulate and monitor the neural activity is hampered by the innate photophobic response of the nematode to short-wavelength light or by the low temporal resolution of photocontrol. Here, we develop boron dipyrromethene (BODIPY)-derived caged compounds that release bioactive phenol derivatives upon illumination in the yellow wavelength range. We show that activation of the transient receptor potential vanilloid 1 (TRPV1) cation channel by spatially targeted optical uncaging of the TRPV1 agonist N-vanillylnonanamide at 580 nm modulates neural activity. Further, neuronal activation by illumination-induced uncaging enables optical control of the behavior of freely moving C. elegans without inducing a photophobic response and without crosstalk between uncaging and simultaneous fluorescence monitoring of neural activity.
Collapse
|
45
|
McDonald NA, Fetter RD, Shen K. Assembly of synaptic active zones requires phase separation of scaffold molecules. Nature 2020; 588:454-458. [PMID: 33208945 DOI: 10.1038/s41586-020-2942-0] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/03/2020] [Indexed: 12/20/2022]
Abstract
The formation of synapses during neuronal development is essential for establishing neural circuits and a nervous system1. Every presynapse builds a core 'active zone' structure, where ion channels cluster and synaptic vesicles release their neurotransmitters2. Although the composition of active zones is well characterized2,3, it is unclear how active-zone proteins assemble together and recruit the machinery required for vesicle release during development. Here we find that the core active-zone scaffold proteins SYD-2 (also known as liprin-α) and ELKS-1 undergo phase separation during an early stage of synapse development, and later mature into a solid structure. We directly test the in vivo function of phase separation by using mutant SYD-2 and ELKS-1 proteins that specifically lack this activity. These mutant proteins remain enriched at synapses in Caenorhabditis elegans, but show defects in active-zone assembly and synapse function. The defects are rescued by introducing a phase-separation motif from an unrelated protein. In vitro, we reconstitute the SYD-2 and ELKS-1 liquid-phase scaffold, and find that it is competent to bind and incorporate downstream active-zone components. We find that the fluidity of SYD-2 and ELKS-1 condensates is essential for efficient mixing and incorporation of active-zone components. These data reveal that a developmental liquid phase of scaffold molecules is essential for the assembly of the synaptic active zone, before maturation into a stable final structure.
Collapse
Affiliation(s)
| | - Richard D Fetter
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA, USA. .,Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
| |
Collapse
|
46
|
Signal Decoding for Glutamate Modulating Egg Laying Oppositely in Caenorhabditis elegans under Varied Environmental Conditions. iScience 2020; 23:101588. [PMID: 33089099 PMCID: PMC7567941 DOI: 10.1016/j.isci.2020.101588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/07/2020] [Accepted: 09/16/2020] [Indexed: 11/24/2022] Open
Abstract
Animals' ability to sense environmental cues and to integrate this information to control fecundity is vital for continuing the species lineage. In this study, we observed that the sensory neurons Amphid neuron (ASHs and ADLs) differentially regulate egg-laying behavior in Caenorhabditis elegans under varied environmental conditions via distinct neuronal circuits. Under standard culture conditions, ASHs tonically release a small amount of glutamate and inhibit Hermaphrodite specific motor neuron (HSN) activities and egg laying via a highly sensitive Glutamate receptor (GLR)-5 receptor. In contrast, under Cu2+ stimulation, ASHs and ADLs may release a large amount of glutamate and inhibit Amphid interneuron (AIA) interneurons via low-sensitivity Glutamate-gated chloride channel (GLC)-3 receptor, thus removing the inhibitory roles of AIAs on HSN activity and egg laying. However, directly measuring the amount of glutamate released by sensory neurons under different conditions and assaying the binding kinetics of receptors with the neurotransmitter are still required to support this study directly. Short-term exposure of CuSO4 evokes hyperactive egg laying ASHs inhibit HSNs and egg laying via GLR-5 receptor under no Cu2+ treatment AIA interneurons suppress HSNs and thus egg laying through ACR-14 signaling Under noxious Cu2+ treatment, ASHs and ADLs suppress AIAs and augment egg laying
Collapse
|
47
|
Cellular Expression and Functional Roles of All 26 Neurotransmitter GPCRs in the C. elegans Egg-Laying Circuit. J Neurosci 2020; 40:7475-7488. [PMID: 32847964 DOI: 10.1523/jneurosci.1357-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/28/2020] [Accepted: 08/13/2020] [Indexed: 01/06/2023] Open
Abstract
Maps of the synapses made and neurotransmitters released by all neurons in model systems, such as Caenorhabditis elegans have left still unresolved how neural circuits integrate and respond to neurotransmitter signals. Using the egg-laying circuit of C. elegans as a model, we mapped which cells express each of the 26 neurotransmitter GPCRs of this organism and also genetically analyzed the functions of all 26 GPCRs. We found that individual neurons express many distinct receptors, epithelial cells often express neurotransmitter receptors, and receptors are often positioned to receive extrasynaptic signals. Receptor knockouts reveal few egg-laying defects under standard laboratory conditions, suggesting that the receptors function redundantly or regulate egg-laying only in specific conditions; however, increasing receptor signaling through overexpression more efficiently reveals receptor functions. This map of neurotransmitter GPCR expression and function in the egg-laying circuit provides a model for understanding GPCR signaling in other neural circuits.SIGNIFICANCE STATEMENT Neurotransmitters signal through GPCRs to modulate activity of neurons, and changes in such signaling can underlie conditions such as depression and Parkinson's disease. To determine how neurotransmitter GPCRs together help regulate function of a neural circuit, we analyzed the simple egg-laying circuit in the model organism C. elegans We identified all the cells that express every neurotransmitter GPCR and genetically analyzed how each GPCR affects the behavior the circuit produces. We found that many neurotransmitter GPCRs are expressed in each neuron, that neurons also appear to use these receptors to communicate with other cell types, and that GPCRs appear to often act redundantly or only under specific conditions to regulate circuit function.
Collapse
|
48
|
Téllez-Arreola JL, Silva M, Martínez-Torres A. MCTP-1 modulates neurotransmitter release in C. elegans. Mol Cell Neurosci 2020; 107:103528. [PMID: 32650044 DOI: 10.1016/j.mcn.2020.103528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 11/30/2022] Open
Abstract
Multiple C2 and Transmembrane Domain Proteins (MCTPs) are putative calcium sensors. Proteins that contain C2 domains play essential roles in membrane trafficking and exocytosis; however, MCTPs functions in neurotransmitter release are not known. Here we report that in C. elegans mctp-1 is under the control of two promoters - one active in the nervous system and the second in the spermatheca. We generated and characterized a loss of function amt1 mutant and compared it to a previously published loss of function mutant (av112). Loss of mctp-1 function causes defects in egg-laying, crawling velocity, and thrashing rates. Both amt1 and av112 mutants are hyposensitive to the acetylcholinesterase blocker aldicarb, suggesting that MCTP-1 may play a role in synaptic vesicle release.
Collapse
Affiliation(s)
- José Luis Téllez-Arreola
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, C.P. 76215 Juriquilla, Querétaro, México; School of Biological Sciences, University of Utah, Salt Lake City, United States
| | - Malan Silva
- School of Biological Sciences, University of Utah, Salt Lake City, United States
| | - Ataúlfo Martínez-Torres
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, C.P. 76215 Juriquilla, Querétaro, México.
| |
Collapse
|
49
|
O'Donnell MP, Fox BW, Chao PH, Schroeder FC, Sengupta P. A neurotransmitter produced by gut bacteria modulates host sensory behaviour. Nature 2020; 583:415-420. [PMID: 32555456 PMCID: PMC7853625 DOI: 10.1038/s41586-020-2395-5] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 03/27/2020] [Indexed: 12/18/2022]
Abstract
Animals coexist in commensal, pathogenic or mutualistic relationships with complex communities of diverse organisms, including microorganisms1. Some bacteria produce bioactive neurotransmitters that have previously been proposed to modulate nervous system activity and behaviours of their hosts2,3. However, the mechanistic basis of this microbiota-brain signalling and its physiological relevance are largely unknown. Here we show that in Caenorhabditis elegans, the neuromodulator tyramine produced by commensal Providencia bacteria, which colonize the gut, bypasses the requirement for host tyramine biosynthesis and manipulates a host sensory decision. Bacterially produced tyramine is probably converted to octopamine by the host tyramine β-hydroxylase enzyme. Octopamine, in turn, targets the OCTR-1 octopamine receptor on ASH nociceptive neurons to modulate an aversive olfactory response. We identify the genes that are required for tyramine biosynthesis in Providencia, and show that these genes are necessary for the modulation of host behaviour. We further find that C. elegans colonized by Providencia preferentially select these bacteria in food choice assays, and that this selection bias requires bacterially produced tyramine and host octopamine signalling. Our results demonstrate that a neurotransmitter produced by gut bacteria mimics the functions of the cognate host molecule to override host control of a sensory decision, and thereby promotes fitness of both the host and the microorganism.
Collapse
Affiliation(s)
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Pin-Hao Chao
- Department of Biology, Brandeis University, Waltham, MA, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA, USA.
| |
Collapse
|
50
|
Cermak N, Yu SK, Clark R, Huang YC, Baskoylu SN, Flavell SW. Whole-organism behavioral profiling reveals a role for dopamine in state-dependent motor program coupling in C. elegans. eLife 2020; 9:e57093. [PMID: 32510332 PMCID: PMC7347390 DOI: 10.7554/elife.57093] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/07/2020] [Indexed: 11/13/2022] Open
Abstract
Animal behaviors are commonly organized into long-lasting states that coordinately impact the generation of diverse motor outputs such as feeding, locomotion, and grooming. However, the neural mechanisms that coordinate these distinct motor programs remain poorly understood. Here, we examine how the distinct motor programs of the nematode C. elegans are coupled together across behavioral states. We describe a new imaging platform that permits automated, simultaneous quantification of each of the main C. elegans motor programs over hours or days. Analysis of these whole-organism behavioral profiles shows that the motor programs coordinately change as animals switch behavioral states. Utilizing genetics, optogenetics, and calcium imaging, we identify a new role for dopamine in coupling locomotion and egg-laying together across states. These results provide new insights into how the diverse motor programs throughout an organism are coordinated and suggest that neuromodulators like dopamine can couple motor circuits together in a state-dependent manner.
Collapse
Affiliation(s)
- Nathan Cermak
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Stephanie K Yu
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Rebekah Clark
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Saba N Baskoylu
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| |
Collapse
|