Meeting Abstract
S10-2.4 Monday, Jan. 7 Gene expression differences underlying sexual dimorphism in ostracod eyes: Insights from transcriptomics RIVERA, Ajna S*; SAJUTHI, Andrea; CARILLO-ZAZUETA, Brenna; LAMPEH, Rebecca; SPEISER, Dan; HU, Brianna; Univ. of the Pacific; Univ. of the Pacific; Univ. of the Pacific; Univ. of Kansas Natural History Museum; Univ. of California, Santa Barbara; Univ. of the Pacific arivera@pacific.edu
The genetics of convergent evolution and switchback evolution is largely unknown. The assumption is that latent gene regulatory networks are redeployed to recreate an ancestral tissue or cell-type. However, the specifics of this are unknown, for example: At what level is the pathway suppressed? How was the network maintained over the evolutionary history of the group? Is the same redeployment strategy used in convergently evolved species? To begin to answer these types of questions we are using transcriptomics, comparative gene expression analysis, and developmental biology to examine a likely case of switchback evolution – the lateral compound eyes in myodocopid ostracods. Our study species, Euphilomedes carcharodonta and E. morini, are of particular interest in that they exhibit dramatic sexual dimorphism of eye morphology. Males have large compound lateral eyes while females have only a tiny rudimentary eye lacking ommatidia. In this way females may represent the ancestral case with eye development suppressed throughout their development while males escape this suppression. Here, we examined the transcriptomes of both embryos and developing male eyes and found 11 of 82 developmental eye genes. After confirming the identity of these genes via phylogenetic methods, we compared gene expression in developing males and females via qPCR and in situ hybridization. We found phototransduction and eye differentiation genes expressed in both male and female eyes, but eye differentiation genes were typically lower in developing female eyes while phototransduction genes showed similar expression levels.
