Meeting Abstract
The phylum Arthropoda is a formidable system for understanding the developmental genetics of novel structures, with an abundance of structural innovations across the diversity of this group. Candidate gene approaches, grounded in established insect models like the fruit fly Drosophila melanogaster, have helped answer questions about some novelties, such as insect wings. This approach, however, is not suitable for study of evolutionary novelties that are restricted to distantly related lineages and is thus inadequate for probing the genetic architecture of structures not found in D. melanogaster or its close relatives. One such structure is the web-weaving organ of spiders, the spinnerets. Here we offer an alternative to the insect-based candidate gene approach toward a more comprehensive understanding of spinneret genetic architecture. We utilized appendage-specific transcriptomes of nascent spinnerets in the tarantula Aphonopelma hentzi and applied differential gene expression (DGE) analyses to derive a list of candidate genes specific to spinneret primordia. Here we share preliminary data for genes identified as highly differentially expressed in the developing spinnerets compared to primordial legs. We also examine leg and spinneret genes’ ages using a phylostratigraphic approach as a test of evolvability. More broadly, our novel application of transcriptomic data and DGE analyses opens the door to identifying genes putatively important in the specification of other appendages types found exclusively in lineages distantly related to insects.
