Abstract
Homeobox genes play crucial roles for the development of multicellular eukaryotes. We have generated a revised list of all homeobox genes for Caenorhabditis elegans and provide a nomenclature for the previously unnamed ones. We show that, out of 103 homeobox genes, 70 are co-orthologous to human homeobox genes. 14 are highly divergent, lacking an obvious ortholog even in other Caenorhabditis species. One of these homeobox genes encodes 12 homeodomains, while three other highly divergent homeobox genes encode a novel type of double homeodomain, termed HOCHOB. To understand how transcription factors regulate cell fate during development, precise spatio-temporal expression data need to be obtained. Using a new imaging framework that we developed, Endrov, we have generated spatio-temporal expression profiles during embryogenesis of over 60 homeobox genes, as well as a number of other developmental control genes using GFP reporters. We used dynamic feedback during recording to automatically adjust the camera exposure time in order to increase the dynamic range beyond the limitations of the camera. We have applied the new framework to examine homeobox gene expression patterns and provide an analysis of these patterns. The methods we developed to analyze and quantify expression data are not only suitable for C. elegans, but can be applied to other model systems or even to tissue culture systems.
Highlights
During embryogenesis, cells divide and their fates become successively more restricted to give rise to different cell types and tissues
This was further verified by creating a HMMER profile that was used to search all ORFs of C. elegans
About 70% of 103 genes have been highly conserved from worms to humans, indicating their fundamental roles in bilaterian development. 15 genes lack orthologs in other Caenorhabditis species, indicating fast evolution and divergence, possibly involved in speciesspecific functions
Summary
Cells divide and their fates become successively more restricted to give rise to different cell types and tissues. Transcription factors play crucial roles in this process by selectively activating specific target genes only in the correct cell types. Homeodomain (HD) proteins are a class of transcription factors that are intimately involved in developmental decisions both in animals and plants (e.g., [1, 2]). Understanding their regulation and function will provide important insights into the cell fate decisions in which they partake. A previous list identified 99 homeobox genes [4]. We provide an updated list of the homeobox genes, provide a completed nomenclature, and assign them to their human orthologs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
