1
|
Catela C, Assimacopoulos S, Chen Y, Tsioras K, Feng W, Kratsios P. The Iroquois ( Iro/Irx ) homeobox genes are conserved Hox targets involved in motor neuron development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596714. [PMID: 38853975 PMCID: PMC11160718 DOI: 10.1101/2024.05.30.596714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The Iroquois (Iro/Irx) homeobox genes encode transcription factors with fundamental roles in animal development. Despite their link to various congenital conditions in humans, our understanding of Iro/Irx gene expression, function, and regulation remains incomplete. Here, we conducted a systematic expression analysis of all six mouse Irx genes in the embryonic spinal cord. We found five Irx genes ( Irx1, Irx2, Irx3, Irx5, and Irx6 ) to be confined mostly to ventral spinal domains, offering new molecular markers for specific groups of post-mitotic motor neurons (MNs). Further, we engineered Irx2, Irx5, and Irx6 mouse mutants and uncovered essential but distinct roles for Irx2 and Irx6 in MN development. Last, we found that the highly conserved regulators of MN development across species, the HOX proteins, directly control Irx gene expression both in mouse and C. elegans MNs, critically expanding the repertoire of HOX target genes in the developing nervous system. Altogether, our study provides important insights into Iro/Irx expression and function in the developing spinal cord, and uncovers an ancient gene regulatory relationship between HOX and Iro/Irx genes.
Collapse
|
2
|
Feng W, Destain H, Smith JJ, Kratsios P. Maintenance of neurotransmitter identity by Hox proteins through a homeostatic mechanism. Nat Commun 2022; 13:6097. [PMID: 36243871 PMCID: PMC9569373 DOI: 10.1038/s41467-022-33781-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
Hox transcription factors play fundamental roles during early patterning, but they are also expressed continuously, from embryonic stages through adulthood, in the nervous system. However, the functional significance of their sustained expression remains unclear. In C. elegans motor neurons (MNs), we find that LIN-39 (Scr/Dfd/Hox4-5) is continuously required during post-embryonic life to maintain neurotransmitter identity, a core element of neuronal function. LIN-39 acts directly to co-regulate genes that define cholinergic identity (e.g., unc-17/VAChT, cho-1/ChT). We further show that LIN-39, MAB-5 (Antp/Hox6-8) and the transcription factor UNC-3 (Collier/Ebf) operate in a positive feedforward loop to ensure continuous and robust expression of cholinergic identity genes. Finally, we identify a two-component design principle for homeostatic control of Hox gene expression in adult MNs: Hox transcriptional autoregulation is counterbalanced by negative UNC-3 feedback. These findings uncover a noncanonical role for Hox proteins during post-embryonic life, critically broadening their functional repertoire from early patterning to the control of neurotransmitter identity.
Collapse
Affiliation(s)
- Weidong Feng
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA
| | - Honorine Destain
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA
| | - Jayson J Smith
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
- University of Chicago Neuroscience Institute, Chicago, IL, USA
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL, USA.
- University of Chicago Neuroscience Institute, Chicago, IL, USA.
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, USA.
| |
Collapse
|
3
|
Clarembaux‐Badell L, Baladrón‐de‐Juan P, Gabilondo H, Rubio‐Ferrera I, Millán I, Estella C, Valverde‐Ortega FS, Cobeta IM, Thor S, Benito‐Sipos J. Dachshund acts with Abdominal-B to trigger programmed cell death in the Drosophila central nervous system at the frontiers of Abd-B expression. Dev Neurobiol 2022; 82:495-504. [PMID: 35796156 PMCID: PMC9544350 DOI: 10.1002/dneu.22894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 11/22/2022]
Abstract
A striking feature of the nervous system pertains to the appearance of different neural cell subtypes at different axial levels. Studies in the Drosophila central nervous system reveal that one mechanism underlying such segmental differences pertains to the segment-specific removal of cells by programmed cell death (PCD). One group of genes involved in segment-specific PCD is the Hox homeotic genes. However, while segment-specific PCD is highly precise, Hox gene expression is evident in gradients, raising the issue of how the Hox gene function is precisely gated to trigger PCD in specific segments at the outer limits of Hox expression. The Drosophila Va neurons are initially generated in all nerve cord segments but removed by PCD in posterior segments. Va PCD is triggered by the posteriorly expressed Hox gene Abdominal-B (Abd-B). However, Va PCD is highly reproducible despite exceedingly weak Abd-B expression in the anterior frontiers of its expression. Here, we found that the transcriptional cofactor Dachshund supports Abd-B-mediated PCD in its anterior domain. In vivo bimolecular fluorescence complementation analysis lends support to the idea that the Dachshund/Abd-B interplay may involve physical interactions. These findings provide an example of how combinatorial codes of transcription factors ensure precision in Hox-mediated PCD in specific segments at the outer limits of Hox expression.
Collapse
Affiliation(s)
- Luis Clarembaux‐Badell
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Pablo Baladrón‐de‐Juan
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Hugo Gabilondo
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Irene Rubio‐Ferrera
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Irene Millán
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Carlos Estella
- Departamento de Biología Molecular and Centro de Biología Molecular Severo OchoaConsejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)Nicolás Cabrera 1MadridSpain
| | - Félix S. Valverde‐Ortega
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Ignacio Monedero Cobeta
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
- Departamento de Fisiología, Facultad de MedicinaUniversidad Autónoma de MadridCantoblancoMadridSpain
| | - Stefan Thor
- School of Biomedical SciencesThe University of QueenslandBrisbaneAustralia
| | - Jonathan Benito‐Sipos
- Departamento de Biología, Facultad de CienciasUniversidad Autónoma de MadridCantoblancoMadridSpain
| |
Collapse
|
4
|
Fernandez-Nicolas A, Ventos-Alfonso A, Kamsoi O, Clark-Hachtel C, Tomoyasu Y, Belles X. Broad complex and wing development in cockroaches. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 147:103798. [PMID: 35662625 DOI: 10.1016/j.ibmb.2022.103798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
In hemimetabolan insects, the transcription factor Broad complex (Br-C) promotes wing growth and development during the nymphal period. We wondered whether Br-C could trigger the initiation of wing development, using the cockroach Blattella germanica as a model. We show that first instar nymphs have their unique identity of these three thoracic segments specified. During embryogenesis, the expression of Br-C and some wing-related genes show two matching waves. The first takes place before the formation of the germ band, which might be involved in the establishment of various developmental fields including a potential "wing field", and the second wave around organogenesis, possibly involved in the initiation of wing development. However, the expression of Br-C in early embryogenesis concentrates in the developing central nervous system, thus not co-localizing with the expression of the typical wing-related gene vestigial, which is expressed at the edge of the thoracic and abdominal segments. This suggests that Br-C is not specifically involved in the establishment of a potential "wing field" in early embryogenesis. Moreover, maternal RNAi for Br-C depletes the first wave of Br-C expression but does not affect the early expression of wing-related genes. As maternal Br-C RNAi did not deplete the second expression wave of Br-C, we could not evaluate if Br-C is involved in the initiation of wing development. Alternatively, using nymphal RNAi of Br-C and Sex combs reduced (Scr), we show that Br-C contributes to the formation of ectopic wing structures that develop in the prothorax when Scr is depleted. The gene most clearly influenced by Br-C RNAi is nubbin (nub), which, in nymphs is crucial for wing growth. Together, these results suggest that Br-C does not specifically contribute to the establishment of the "wing field", but it does seem important later, in the initiation of wing development, enhancing the expression of wing-related genes, especially nub. This supports the hypothesis previously proposed by the authors, whereby Br-C might have facilitated the evolution of holometaboly. However, there is no doubt that other factors have also contributed to this evolution.
Collapse
Affiliation(s)
| | - Alba Ventos-Alfonso
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Orathai Kamsoi
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Courtney Clark-Hachtel
- Department of Biology, Miami University, 700E High St, Pearson Hall, Oxford, OH, 45056, USA
| | - Yoshinori Tomoyasu
- Department of Biology, Miami University, 700E High St, Pearson Hall, Oxford, OH, 45056, USA
| | - Xavier Belles
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain.
| |
Collapse
|
5
|
Feng W, Li Y, Kratsios P. Emerging Roles for Hox Proteins in the Last Steps of Neuronal Development in Worms, Flies, and Mice. Front Neurosci 2022; 15:801791. [PMID: 35185450 PMCID: PMC8855150 DOI: 10.3389/fnins.2021.801791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/31/2021] [Indexed: 12/28/2022] Open
Abstract
A remarkable diversity of cell types characterizes every animal nervous system. Previous studies provided important insights into how neurons commit to a particular fate, migrate to the right place and form precise axodendritic patterns. However, the mechanisms controlling later steps of neuronal development remain poorly understood. Hox proteins represent a conserved family of homeodomain transcription factors with well-established roles in anterior-posterior (A-P) patterning and the early steps of nervous system development, including progenitor cell specification, neuronal migration, cell survival, axon guidance and dendrite morphogenesis. This review highlights recent studies in Caenorhabditis elegans, Drosophila melanogaster and mice that suggest new roles for Hox proteins in processes occurring during later steps of neuronal development, such as synapse formation and acquisition of neuronal terminal identity features (e.g., expression of ion channels, neurotransmitter receptors, and neuropeptides). Moreover, we focus on exciting findings suggesting Hox proteins are required to maintain synaptic structures and neuronal terminal identity during post-embryonic life. Altogether, these studies, in three model systems, support the hypothesis that certain Hox proteins are continuously required, from early development throughout post-embryonic life, to build and maintain a functional nervous system, significantly expanding their functional repertoire beyond the control of early A-P patterning.
Collapse
Affiliation(s)
- Weidong Feng
- Department of Neurobiology, University of Chicago, Chicago, IL, United States
- University of Chicago Neuroscience Institute, Chicago, IL, United States
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, United States
| | - Yinan Li
- Department of Neurobiology, University of Chicago, Chicago, IL, United States
- University of Chicago Neuroscience Institute, Chicago, IL, United States
- Committee on Neurobiology, University of Chicago, Chicago, IL, United States
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL, United States
- University of Chicago Neuroscience Institute, Chicago, IL, United States
- *Correspondence: Paschalis Kratsios,
| |
Collapse
|
6
|
Sajadi F, Uyuklu A, Paputsis C, Lajevardi A, Wahedi A, Ber LT, Matei A, Paluzzi JPV. CAPA neuropeptides and their receptor form an anti-diuretic hormone signaling system in the human disease vector, Aedes aegypti. Sci Rep 2020; 10:1755. [PMID: 32020001 PMCID: PMC7000730 DOI: 10.1038/s41598-020-58731-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/20/2020] [Indexed: 01/07/2023] Open
Abstract
Insect CAPA neuropeptides are homologs of mammalian neuromedin U and are known to influence ion and water balance by regulating the activity of the Malpighian 'renal' tubules (MTs). Several diuretic hormones are known to increase primary fluid and ion secretion by insect MTs and, in adult female mosquitoes, a calcitonin-related peptide (DH31) called mosquito natriuretic peptide, increases sodium secretion to compensate for the excess salt load acquired during blood-feeding. An endogenous mosquito anti-diuretic hormone was recently described, having potent inhibitory activity against select diuretic hormones, including DH31. Herein, we functionally deorphanized, both in vitro and in vivo, a mosquito anti-diuretic hormone receptor (AedaeADHr) with expression analysis indicating highest enrichment in the MTs where it is localized within principal cells. Characterization using a heterologous in vitro system demonstrated the receptor was highly sensitive to mosquito CAPA neuropeptides while in vivo, AedaeADHr knockdown abolished CAPA-induced anti-diuretic control of DH31-stimulated MTs. CAPA neuropeptides are produced within a pair of neurosecretory cells in each of the abdominal ganglia, whose axonal projections innervate the abdominal neurohaemal organs, where these neurohormones are released into circulation. Lastly, pharmacological inhibition of nitric oxide synthase (NOS) and protein kinase G (PKG) signaling eliminated anti-diuretic activity of CAPA, highlighting the role of the second messenger cGMP and NOS/PKG in this anti-diuretic signaling pathway.
Collapse
Affiliation(s)
- Farwa Sajadi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Ali Uyuklu
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Christine Paputsis
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Aryan Lajevardi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Azizia Wahedi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Lindsay Taylor Ber
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Andreea Matei
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Jean-Paul V Paluzzi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada.
| |
Collapse
|