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Sokolowski DJ, Vasquez OE, Wilson MD, Sokolowski MB, Anreiter I. Transcriptomic effects of the foraging gene shed light on pathways of pleiotropy and plasticity. Ann N Y Acad Sci 2023; 1526:99-113. [PMID: 37350250 DOI: 10.1111/nyas.15015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Genes are often pleiotropic and plastic in their expression, features which increase and diversify the functionality of the genome. The foraging (for) gene in Drosophila melanogaster is highly pleiotropic and a long-standing model for studying individual differences in behavior and plasticity from ethological, evolutionary, and genetic perspectives. Its pleiotropy is known to be linked to its complex molecular structure; however, the downstream pathways and interactors remain mostly elusive. To uncover these pathways and interactors and gain a better understanding of how pleiotropy and plasticity are achieved at the molecular level, we explore the effects of different for alleles on gene expression at baseline and in response to 4 h of food deprivation, using RNA sequencing analysis in different Drosophila larval tissues. The results show tissue-specific transcriptomic dynamics influenced by for allelic variation and food deprivation, as well as genotype by treatment interactions. Differentially expressed genes yielded pathways linked to previously described for phenotypes and several potentially novel phenotypes. Together, these findings provide putative genes and pathways through which for might regulate its varied phenotypes in a pleiotropic, plastic, and gene-structure-dependent manner.
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Affiliation(s)
- Dustin J Sokolowski
- Genetics and Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Michael D Wilson
- Genetics and Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Program in Child and Brain Development, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - Ina Anreiter
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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2
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Vasquez OE, Allen AM, So AKC, Nguyen QH, Krause HM, Levine JD, Sokolowski MB. Characterizing the Protein Isoforms of foraging ( for), the PKGI Ortholog in Drosophila melanogaster. Int J Mol Sci 2023; 24:10219. [PMID: 37373366 DOI: 10.3390/ijms241210219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
The foraging (for) gene of Drosophila melanogaster encodes a cGMP-dependent protein kinase (PKG), which is a major effector of the cGMP signaling pathway involved in the regulation of behaviour and metabolic traits. Despite being well studied at the transcript level, little is known about the for gene at the protein level. Here, we provide a detailed characterization of the for gene protein (FOR) products and present new tools for their study, including five isoform-specific antibodies and a transgenic strain that carries an HA-labelled for allele (forBAC::HA). Our results showed that multiple FOR isoforms were expressed in the larval and adult stages of D. melanogaster and that the majority of whole-body FOR expression arises from three (P1, P1α, and P3) of eight putative protein isoforms. We found that FOR expression differed between the larval and adult stages and between the dissected larval organs we analyzed, which included the central nervous system (CNS), fat body, carcass, and intestine. Moreover, we showed that the FOR expression differed between two allelic variants of the for gene, namely, fors (sitter) and forR (rover), that are known to differ in many food-related traits. Together, our in vivo identification of FOR isoforms and the existence of temporal, spatial, and genetic differences in their expression lay the groundwork for determining their functional significance.
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Affiliation(s)
- Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Aaron M Allen
- Centre for Neural Circuits and Behaviour, Oxford University, Oxford OX1 3SR, UK
| | - Anthony K-C So
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Quynh H Nguyen
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Henry M Krause
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Joel D Levine
- Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, ON M5G 1M1, Canada
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3
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Gallot A, Desouhant E, Lhuillier V, Lepetit D, El Filali A, Mouton L, Vieira-Heddi C, Amat I. The for gene as one of the drivers of foraging variations in a parasitic wasp. Mol Ecol 2022; 32:1760-1776. [PMID: 36571434 DOI: 10.1111/mec.16834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/08/2022] [Accepted: 12/22/2022] [Indexed: 12/27/2022]
Abstract
Foraging behaviours encompass strategies to locate resources and to exploit them. In many taxa, these behaviours are driven by a major gene called for, but the mechanisms of gene regulation vary between species. In the parasitoid wasp Venturia canescens, sexual and asexual populations coexist in sympatry but differ in life-history traits, physiology and behaviours, which could impact their foraging strategies. Here, we explored the molecular bases underpinning divergence in behaviours by testing two mutually nonexclusive hypotheses: first, the divergence in the for gene correlates with differences in foraging strategies, and second, the latter rely on a divergence in whole-genome expression. Using comparative genomics, we showed that the for gene was conserved across insects considering both sequence and gene model complexity. Polymorphism analysis did not support the occurrence of two allelic variants diverging across the two populations, yet the asexual population exhibited less polymorphism than the sexual population. Sexual and asexual transcriptomes split sharply, with 10.9% differentially expressed genes, but these were not enriched in behaviour-related genes. We showed that the for gene was more highly expressed in asexual female heads than in sexual heads and that those differences correlate with divergence in foraging behaviours in our experiment given that asexuals explored the environment more and exploited more host patches. Overall, these results suggested that fine tuning of for gene expression between populations may have led to distinct foraging behaviours. We hypothesized that reproductive polymorphism and coexistence in sympatry of sexual and asexual populations specialized to different ecological niches via divergent optima on phenotypic traits could imply adaptation through different expression patterns of the for gene and at many other loci throughout the genome.
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Affiliation(s)
- Aurore Gallot
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Emmanuel Desouhant
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Vincent Lhuillier
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - David Lepetit
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Adil El Filali
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Laurence Mouton
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Cristina Vieira-Heddi
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Isabelle Amat
- LBBE - Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France
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4
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Dason JS, Anreiter I, Wu CF. Transcending boundaries: from quantitative genetics to single genes. J Neurogenet 2021; 35:95-98. [PMID: 34544325 DOI: 10.1080/01677063.2021.1960519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Jeffrey S Dason
- Department of Biomedical Sciences, University of Windsor, Windsor, Canada
| | - Ina Anreiter
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Chun-Fang Wu
- Department of Biology, University of Iowa, Iowa City, IA, USA
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5
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Allen AM, B Sokolowski M. Expression of the foraging gene in adult Drosophila melanogaster. J Neurogenet 2021; 35:192-212. [PMID: 34382904 PMCID: PMC8846931 DOI: 10.1080/01677063.2021.1941946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The foraging gene in Drosophila melanogaster, which encodes a cGMP-dependent protein kinase, is a highly conserved, complex gene with multiple pleiotropic behavioral and physiological functions in both the larval and adult fly. Adult foraging expression is less well characterized than in the larva. We characterized foraging expression in the brain, gastric system, and reproductive systems using a T2A-Gal4 gene-trap allele. In the brain, foraging expression appears to be restricted to multiple sub-types of glia. This glial-specific cellular localization of foraging was supported by single-cell transcriptomic atlases of the adult brain. foraging is extensively expressed in most cell types in the gastric and reproductive systems. We then mapped multiple cis-regulatory elements responsible for parts of the observed expression patterns by a nested cloned promoter-Gal4 analysis. The mapped cis-regulatory elements were consistently modular when comparing the larval and adult expression patterns. These new data using the T2A-Gal4 gene-trap and cloned foraging promoter fusion GAL4's are discussed with respect to previous work using an anti-FOR antibody, which we show here to be non-specific. Future studies of foraging's function will consider roles for glial subtypes and peripheral tissues (gastric and reproductive systems) in foraging's pleiotropic behavioral and physiological effects.
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Affiliation(s)
- Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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6
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Krill JL, Dawson-Scully K. Characterization of a novel stimulus-induced glial calcium wave in Drosophila larval peripheral segmental nerves and its role in PKG-modulated thermoprotection. J Neurogenet 2021; 35:221-235. [PMID: 34309496 DOI: 10.1080/01677063.2021.1941945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Insects, as poikilotherms, have adaptations to deal with wide ranges in temperature fluctuation. Allelic variations in the foraging gene that encodes a cGMP dependent protein kinase, were discovered to have effects on behavior in Drosophila by Dr. Marla Sokolowski in 1980. This single gene has many pleiotropic effects and influences feeding behavior, metabolic storage, learning and memory and has been shown to affect stress tolerance. PKG regulation affects motoneuronal thermotolerance in Drosophila larvae as well as adults. While the focus of thermotolerance studies has been on the modulation of neuronal function, other cell types have been overlooked. Because glia are vital to neuronal function and survival, we wanted to determine if glia play a role in thermotolerance as well. In our investigation, we discovered a novel calcium wave at the larval NMJ and set out to characterize the wave's dynamics and the potential mechanism underlying the wave prior to determining what effect, if any, PKG modulation has on the thermotolerance of glia cells. Using pharmacology, we determined that calcium buffering mechanisms of the mitochondria and endoplasmic reticulum play a role in the propagation of our novel glial calcium wave. By coupling pharmacology with genetic manipulation using RNA interference (RNAi), we found that PKG modulation in glia alters thermoprotection of function as well as glial calcium wave dynamics.
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Affiliation(s)
- Jennifer L Krill
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
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7
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Abstract
The pursuit of understanding behavior has led to investigations of how genes, the environment, and the nervous system all work together to produce and influence behavior, giving rise to a field of research known as behavioral neurogenetics. This review focuses on the research journeys of two pioneers of aspects of behavioral neurogenetic research: Dr. Marla Sokolowski and Dr. Catharine Rankin as examples of how different approaches have been used to understand relationships between genes and behavior. Marla Sokolowski's research is centered around the discovery and analysis of foraging, a gene responsible for the natural behavioral polymorphism of Drosophila melanogaster larvae foraging behavior. Catharine Rankin's work began with demonstrating the ability to learn in Caenorhabditis elegans and then setting out to investigate the mechanisms underlying the "simplest" form of learning, habituation. Using these simple invertebrate organisms both investigators were able to perform in-depth dissections of behavior at genetic and molecular levels. By exploring their research and highlighting their findings we present ways their work has furthered our understanding of behavior and contributed to the field of behavioral neurogenetics.
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Affiliation(s)
- Aaron P Reiss
- Department of Psychology, University of British Columbia, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Catharine H Rankin
- Department of Psychology, University of British Columbia, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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8
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Greenspan RJ. Learning about quantitative genetics from Marla Sokolowski. J Neurogenet 2021; 35:110-111. [PMID: 34128769 DOI: 10.1080/01677063.2021.1940167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Marla Sokolowski is a true pioneer in behavioral genetics, having made the first molecular delineation of a naturally occurring behavioral polymorphism in her work on the foraging locus in Drosophila melanogaster. The gene was subsequently found to be responsible for behavioral variants and types in many other species, both invertebrate and mammal (human). The path to get there is a paradigmatic example of how to use the power of genetic analysis, including some rather esoteric techniques, to zero in on a gene and delineate its molecular identity and its pleiotropic roles.
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Affiliation(s)
- Ralph J Greenspan
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA, USA
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9
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Abstract
Drosophila melanogaster displays social behaviors including courtship, mating, aggression, and group foraging. Recent studies employed social network analyses (SNAs) to show that D. melanogaster strains differ in their group behavior, suggesting that genes influence social network phenotypes. Aside from genes associated with sensory function, few studies address the genetic underpinnings of these networks. The foraging gene (for) is a well-established example of a pleiotropic gene that regulates multiple behavioral phenotypes and their plasticity. In D. melanogaster, there are two naturally occurring alleles of for called rover and sitter that differ in their larval and adult food-search behavior as well as other behavioral phenotypes. Here, we hypothesize that for affects behavioral elements required to form social networks and the social networks themselves. These effects are evident when we manipulate gene dosage. We found that flies of the rover and sitter strains exhibit differences in duration, frequency, and reciprocity of pairwise interactions, and they form social networks with differences in assortativity and global efficiency. Consistent with other adult phenotypes influenced by for, rover-sitter heterozygotes show intermediate patterns of dominance in many of these characteristics. Multiple generations of backcrossing a rover allele into a sitter strain showed that many but not all of these rover-sitter differences may be attributed to allelic variation at for. Our findings reveal the significant role that for plays in affecting social network properties and their behavioral elements in Drosophila melanogaster.
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Affiliation(s)
- Nawar Alwash
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
| | - Joel D Levine
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
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10
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Oepen AS, Catalano JL, Azanchi R, Kaun KR. The foraging gene affects alcohol sensitivity, metabolism and memory in Drosophila. J Neurogenet 2021; 35:236-248. [PMID: 34092172 DOI: 10.1080/01677063.2021.1931178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The genetic basis of alcohol use disorder (AUD) is complex. Understanding how natural genetic variation contributes to alcohol phenotypes can help us identify and understand the genetic basis of AUD. Recently, a single nucleotide polymorphism in the human foraging (for) gene ortholog, Protein Kinase cGMP-Dependent 1 (PRKG1), was found to be associated with stress-induced risk for alcohol abuse. However, the mechanistic role that PRKG1 plays in AUD is not well understood. We use natural variation in the Drosophila for gene to describe how variation of cGMP-dependent protein kinase (PKG) activity modifies ethanol-induced phenotypes. We found that variation in for affects ethanol-induced increases in locomotion and memory of the appetitive properties of ethanol intoxication. Further, these differences may stem from the ability to metabolize ethanol. Together, this data suggests that natural variation in PKG modulates cue reactivity for alcohol, and thus could influence alcohol cravings by differentially modulating metabolic and behavioral sensitivities to alcohol.
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Affiliation(s)
- Anne S Oepen
- Department of Neuroscience, Brown University, Providence, RI, USA.,Masters Program in Developmental, Neuronal and Behavioral Biology, Georg-August-University, Göttingen, Germany
| | - Jamie L Catalano
- Department of Neuroscience, Brown University, Providence, RI, USA.,Molecular Pharmacology and Physiology Graduate Program, Brown University, Providence, RI, USA
| | - Reza Azanchi
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Karla R Kaun
- Department of Neuroscience, Brown University, Providence, RI, USA
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11
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Dason JS, Sokolowski MB. A cGMP-dependent protein kinase, encoded by the Drosophila foraging gene, regulates neurotransmission through changes in synaptic structure and function. J Neurogenet 2021; 35:213-220. [PMID: 33998378 DOI: 10.1080/01677063.2021.1905639] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A cGMP-dependent protein kinase (PKG) encoded by the Drosophila foraging (for) gene regulates both synaptic structure (nerve terminal growth) and function (neurotransmission) through independent mechanisms at the Drosophila larval neuromuscular junction (nmj). Glial for is known to restrict nerve terminal growth, whereas presynaptic for inhibits synaptic vesicle (SV) exocytosis during low frequency stimulation. Presynaptic for also facilitates SV endocytosis during high frequency stimulation. for's effects on neurotransmission can occur independent of any changes in nerve terminal growth. However, it remains unclear if for's effects on neurotransmission affect nerve terminal growth. Furthermore, it's possible that for's effects on synaptic structure contribute to changes in neurotransmission. In the present study, we examined these questions using RNA interference to selectively knockdown for in presynaptic neurons or glia at the Drosophila larval nmj. Consistent with our previous findings, presynaptic knockdown of for impaired SV endocytosis, whereas knockdown of glial for had no effect on SV endocytosis. Surprisingly, we found that knockdown of either presynaptic or glial for increased neurotransmitter release in response to low frequency stimulation. Knockdown of presynaptic for did not affect nerve terminal growth, demonstrating that for's effects on neurotransmission does not alter nerve terminal growth. In contrast, knockdown of glial for enhanced nerve terminal growth. This enhanced nerve terminal growth was likely the cause of the enhanced neurotransmitter release seen following knockdown of glial for. Overall, we show that for can affect neurotransmitter release by regulating both synaptic structure and function.
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Affiliation(s)
- Jeffrey S Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Biomedical Sciences, University of Windsor, Windsor, Canada
| | - Marla B Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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12
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Anreiter I, Allen AM, Vasquez OE, To L, Douglas SJ, Alvarez JV, Ewer J, Sokolowski MB. The Drosophila foraging gene plays a vital role at the start of metamorphosis for subsequent adult emergence. J Neurogenet 2021; 35:179-191. [PMID: 33944658 DOI: 10.1080/01677063.2021.1914608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The foraging (for) gene has been extensively studied in many species for its functions in development, physiology, and behavior. It is common for genes that influence behavior and development to be essential genes, and for has been found to be an essential gene in both fruit flies and mammals, with for mutants dying before reaching the adult stage. However, the biological process underlying the lethality associated with this gene is not known. Here, we show that in Drosophila melanogaster, some but not all gene products of for are essential for survival. Specifically, we show that promoter 3 of for, but not promoters 1, 2, and 4 are required for survival past pupal stage. We use full and partial genetic deletions of for, and temperature-restricted knock-down of the gene to further investigate the stage of lethality. While deletion analysis shows that flies lacking for die at the end of pupal development, as pharate adults, temperature-restricted knock-down shows that for is only required at the start of pupal development, for normal adult emergence (AE) and viability. We further show that the inability of these mutants to emerge from their pupal cases is linked to deficiencies in emergence behaviors, caused by a possible energy deficiency, and finally, that the lethality of for mutants seems to be linked to protein isoform P3, transcribed from for promoter 3.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada.,Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
| | - Oscar E Vasquez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Lydia To
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada
| | - Scott J Douglas
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Javier V Alvarez
- Centro Interdisciplinario de Neurociencia de Valparaíso e Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - John Ewer
- Centro Interdisciplinario de Neurociencia de Valparaíso e Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
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13
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Abstract
The Drosophila melanogaster foraging (for) gene is a well-established example of a gene with major effects on behavior and natural variation. This gene is best known for underlying the behavioral strategies of rover and sitter foraging larvae, having been mapped and named for this phenotype. Nevertheless, in the last three decades an extensive array of studies describing for's role as a modifier of behavior in a wide range of phenotypes, in both Drosophila and other organisms, has emerged. Furthermore, recent work reveals new insights into the genetic and molecular underpinnings of how for affects these phenotypes. In this article, we discuss the history of the for gene and its role in natural variation in behavior, plasticity, and behavioral pleiotropy, with special attention to recent findings on the molecular structure and transcriptional regulation of this gene.
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Affiliation(s)
- Ina Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
| | - Marla B Sokolowski
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada;
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14
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Dason JS, Cheung A, Anreiter I, Montemurri VA, Allen AM, Sokolowski MB. Drosophila melanogaster foraging regulates a nociceptive-like escape behavior through a developmentally plastic sensory circuit. Proc Natl Acad Sci U S A 2020; 117:23286-91. [PMID: 31213548 DOI: 10.1073/pnas.1820840116] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Painful or threatening experiences trigger escape responses that are guided by nociceptive neuronal circuitry. Although some components of this circuitry are known and conserved across animals, how this circuitry is regulated at the genetic and developmental levels is mostly unknown. To escape noxious stimuli, such as parasitoid wasp attacks, Drosophila melanogaster larvae generate a curling and rolling response. Rover and sitter allelic variants of the Drosophila foraging (for) gene differ in parasitoid wasp susceptibility, suggesting a link between for and nociception. By optogenetically activating cells associated with each of for's promoters (pr1-pr4), we show that pr1 cells regulate larval escape behavior. In accordance with rover and sitter differences in parasitoid wasp susceptibility, we found that rovers have higher pr1 expression and increased sensitivity to nociception relative to sitters. The for null mutants display impaired responses to thermal nociception, which are rescued by restoring for expression in pr1 cells. Conversely, knockdown of for in pr1 cells phenocopies the for null mutant. To gain insight into the circuitry underlying this response, we used an intersectional approach and activity-dependent GFP reconstitution across synaptic partners (GRASP) to show that pr1 cells in the ventral nerve cord (VNC) are required for the nociceptive response, and that multidendritic sensory nociceptive neurons synapse onto pr1 neurons in the VNC. Finally, we show that activation of the pr1 circuit during development suppresses the escape response. Our data demonstrate a role of for in larval nociceptive behavior. This function is specific to for pr1 neurons in the VNC, guiding a developmentally plastic escape response circuit.
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15
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Dason JS, Allen AM, Vasquez OE, Sokolowski MB. Distinct functions of a cGMP-dependent protein kinase in nerve terminal growth and synaptic vesicle cycling. J Cell Sci 2019; 132:jcs.227165. [DOI: 10.1242/jcs.227165] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/26/2019] [Indexed: 01/20/2023] Open
Abstract
Sustained neurotransmission requires the tight coupling of synaptic vesicle (SV) exocytosis and endocytosis. The mechanisms underlying this coupling are poorly understood. We tested the hypothesis that a cGMP-dependent protein kinase (PKG), encoded by the foraging (for) gene in Drosophila melanogaster, is critical for this process using a for null mutant, genomic rescues, and tissue specific rescues. We uncoupled FOR's exocytic and endocytic functions in neurotransmission using a temperature-sensitive shibire mutant in conjunction with fluorescein-assisted light inactivation of FOR. We discovered a dual role for presynaptic FOR, where FOR inhibits SV exocytosis during low frequency stimulation by negatively regulating presynaptic Ca2+ levels and maintains neurotransmission during high frequency stimulation by facilitating SV endocytosis. Additionally, glial FOR negatively regulated nerve terminal growth through TGF-β signaling and this developmental effect was independent from FOR's effects on neurotransmission. Overall, FOR plays a critical role in coupling SV exocytosis and endocytosis, thereby balancing these two components to maintain sustained neurotransmission.
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Affiliation(s)
- Jeffrey S. Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Biological Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Aaron M. Allen
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Present Address: Centre for Neural Circuits and Behaviour, University of Oxford, OX1 3SR Oxford, UK
| | - Oscar E. Vasquez
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Marla B. Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, M5G 1M1, Canada
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Dason JS, Sokolowski MB, Wu CF. A reductionist approach to understanding the nervous system: the Harold Atwood legacy. J Neurogenet 2018; 32:127-130. [PMID: 30484389 DOI: 10.1080/01677063.2018.1504044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Jeffrey S Dason
- a Department of Biological Sciences , University of Windsor , Windsor , Canada
| | - Marla B Sokolowski
- b Department of Cell & Systems Biology , University of Toronto , Toronto , Canada.,c Department of Ecology & Evolutionary Biology , University of Toronto , Toronto , Canada.,d Child and Brain Development Program , Canadian Institute for Advanced Research (CIFAR) , Toronto , Canada
| | - Chun-Fang Wu
- e Department of Biology , University of Iowa , Iowa City , IA , USA
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