Meeting Abstract
Venoms are complex phenotypes with a large and diverse set of interacting molecular components. Spider venoms of have deep evolutionary histories, and are strikingly complex. There are many phylogenetically widespread toxin lineages in spiders, however some have narrow distributions and reflect rare recruitment events of new venom toxin activities. The sicariid spider family includes the brown recluse and over 100 congenerics in the genus Loxosceles. These are generalists living in dry habitats and caves. Brown recluse bites cause dermonecrosis in mammals. A toxin gene family with phospholipase activity (SicTox) causes these lesions. Comparative analyses indicate SicTox expression in venoms is limited to sicariids, consistent with recruitment of the gene family before the most recent common ancestor of this taxon. We address the hypothesis that with the evolutionary recruitment of new bioactive toxins in venoms, other lineages will undergo changes as part of the changing molecular functional complex. We predict that, coincident with recruitment of SicTox proteins, other toxin lineages have changed in presence, abundance, or adaptive evolution of function. We present comparative venomic data that integrate HiSeq transcriptomes of venom glands, and Orbitrap proteomic analyses that identify and compare gene families contributing to venom proetomes. We also present results of comparative analyses of evolutionary dynamics of these gene family lineages. Our dataset includes sampling across representatives of diverse sicariids with common ancestry spanning ~ 10 – 120 million years, and a range of non-sicariid haplogyne spiders including three taxa in their sister lineage (Drymusa, Periogops, and Scytodes) and other haplogynes including pholcids and plectreurids.
