One goal of evolutionary developmental biology is to understand the mechanisms that underlie the regulation and evolution of embryogenesis among different species. One approach to answer these questions is to study and compare the expression and function of “toolbox” genes in different lineages. Members of two conserved gene families, Hes and Sox, are involved in both segmentation and neurogenesis in different metazoans. Genes such as hairy and Dichaete are involved in the segmentation cascade in Drosophila melanogaster, whereas deadpan and Sox21B acts in the regulation of the neurogenic precursors in the same species. To broaden our understanding of the evolution and function of these genes, for this project, I studied them in the commonhouse spider P. tepidariorum: an emergent organism to studies in comparative embryology and genetics, and which has experienced a whole genome duplication in its evolutionary history. I characterized the expression of four Hes-like genes and fifteen Sox genes in this species. Briefly, hairy and Sox21B-1 are expressed in prosoma as well as in the posterior segment addition zone and forming segments. deadpan, hey, side, SoxNeuro, Sox C-1 and Sox D-2 are expressed in the central nervous system, and Sox E-2 and Sox F-2 in the mechanoceptors of the walking limbs and peripheral nervous system. I also carried out functional analysis of Sox21b-1 and demonstrated its involvement in the gene regulatory network that is responsible for the posterior segment addition in the spider, as well as a striking relation with secondary layers formation. Finally, I generated new resources to help develop new functional tools in P. tepidariorum in order to make genomic manipulations in this species, as well as to improve techniques such as live imaging and in situ hybridization. Taken together my research embraced different aspects of the spider embryogenesis and prove that the chelicerates are emerging research systems to the study of evolutionary developmental biology.
Permanent link to this resource: https://doi.org/10.24384/s2b9-xe14
Bonatto Paese, Christian L.
Faculty of Health and Life SciencesDepartment of Biological and Medical Sciences
Year: 2018
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