Widespread employment of conserved C. elegans homeobox genes in neuronal identity specification Journal Article


Authors: Reilly, M. B.; Tekieli, T.; Cros, C.; Aguilar, G. R.; Lao, J.; Toker, I. A.; Vidal, B.; Leyva-Díaz, E.; Bhattacharya, A.; Cook, S. J.; Smith, J. J.; Kovacevic, I.; Gulez, B.; Fernandez, R. W.; Bradford, E. F.; Ramadan, Y. H.; Kratsios, P.; Bao, Z.; Hobert, O.
Article Title: Widespread employment of conserved C. elegans homeobox genes in neuronal identity specification
Abstract: Homeobox genes are prominent regulators of neuronal identity, but the extent to which their function has been probed in animal nervous systems remains limited. In the nematode Caenorhabditis elegans, each individual neuron class is defined by the expression of unique combinations of homeobox genes, prompting the question of whether each neuron class indeed requires a homeobox gene for its proper identity specification. We present here progress in addressing this question by extending previous mutant analysis of homeobox gene family members and describing multiple examples of homeobox gene function in different parts of the C. elegans nervous system. To probe homeobox function, we make use of a number of reporter gene tools, including a novel multicolor reporter transgene, NeuroPAL, which permits simultaneous monitoring of the execution of multiple differentiation programs throughout the entire nervous system. Using these tools, we add to the previous characterization of homeobox gene function by identifying neuronal differentiation defects for 14 homeobox genes in 24 distinct neuron classes that are mostly unrelated by location, function and lineage history. 12 of these 24 neuron classes had no homeobox gene function ascribed to them before, while in the other 12 neuron classes, we extend the combinatorial code of transcription factors required for specifying terminal differentiation programs. Furthermore, we demonstrate that in a particular lineage, homeotic identity transformations occur upon loss of a homeobox gene and we show that these transformations are the result of changes in homeobox codes. Combining the present with past analyses, 113 of the 118 neuron classes of C. elegans are now known to require a homeobox gene for proper execution of terminal differentiation programs. Such broad deployment indicates that homeobox function in neuronal identity specification may be an ancestral feature of animal nervous systems.
Keywords: dna binding protein; genetics; dna-binding proteins; animal; metabolism; animals; transcription factor; cell differentiation; neurons; transcription factors; gene expression regulation; gene expression regulation, developmental; caenorhabditis elegans; nerve cell; genes, homeobox; caenorhabditis elegans protein; caenorhabditis elegans proteins; employment; homeobox
Journal Title: PLoS Genetics
Volume: 18
Issue: 9
ISSN: 1553-7390
Publisher: Public Library of Science  
Date Published: 2022-09-30
Start Page: e1010372
Language: English
DOI: 10.1371/journal.pgen.1010372
PUBMED: 36178933
PROVIDER: scopus
PMCID: PMC9524666
DOI/URL:
Notes: Article -- Export Date: 1 November 2022 -- Source: Scopus
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  1. Zhirong Bao
    56 Bao