Publication Date:
2013-12-28
Description:
Background: The genetics of development in the nematode Caenorhabditis elegans has been described in exquisitedetail. The phylum Nematoda has two classes: Chromadorea (which includes C. elegans) and theEnoplea. While the development of many chromadorean species resembles closely that of C. elegans,enoplean nematodes show markedly different patterns of early cell division and cell fate assignment.Embryogenesis of the enoplean Romanomermis culicivorax has been studied in detail, but the geneticcircuitry underpinning development in this species has not been explored. Results: We generated a draft genome for R. culicivorax and compared its gene content with that of C. elegans,a second enoplean, the vertebrate parasite Trichinella spiralis, and a representative arthropod,Tribolium castaneum. This comparison revealed that R. culicivorax has retained components of theconserved ecdysozoan developmental gene toolkit lost in C. elegans. T. spiralis has independentlylost even more of this toolkit than has C. elegans. However, the C. elegans toolkit is not simply depauperate, as many novel genes essential for embryogenesis in C. elegans are not found in, or haveonly extremely divergent homologues in R. culicivorax and T. spiralis. Our data imply fundamentaldifferences in the genetic programmes not only for early cell specification but also others such asvulva formation and sex determination. Conclusions: Despite the apparent morphological conservatism, major differences in the molecular logic of developmenthave evolved within the phylum Nematoda. R. culicivorax serves as a tractable system to contrast C. elegans and understand how divergent genomic and thus regulatory backgrounds nevertheless generate a conserved phenotype. The R. culicivorax draft genome will promote use of this species as a research model.
Electronic ISSN:
1471-2164
Topics:
Biology
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