Meeting Abstract

26.4  Friday, Jan. 4  Genomic and gene regulatory signatures of cryptozoic adaptation in the red flour beetle Tribolium castaneum FRIEDRICH, Markus*; BAO, Riyue ; JACKOWSKA, Magdalena; LIU, Zhenyi; Wayne State University friedrichm@wayne.edu

The many ways in which cryptozoic animals adapted to the light deprived biota of crevices, caverns, and caves arguably count as prime manifestations of the body plan molding power of natural selection. Loss of visual organs and body pigmentation are just some of the well studied phenotypic effects of long-term adaptation to life in caves. Little, however, is known regarding possible genomic or gene regulatory consequences. Here I present first insights from the recently sequenced genome of the red flour beetle Tribolium castaneum. Like Tenebrionidae in general, the stored grain pest Tribolium avoids broad daylight. All life cycle stages hide in tunnels driven through the food substrate suggesting a moderate degree of cryptozoic adaptation. Intriguingly, the genome sequence reveals a massive expansion of olfactory and gustatory receptor genes while the number of visual receptor genes (rhodopsins) is exceptionally reduced compared to honeybee and Drosophila. Gene expression studies in our lab show that the single long wavelength sensitive rhodopsin of Tribolium is expressed in an unusual pattern that explains the loss of widely conserved blue sensitive rhodopsin genes in this species and may enhance light sensitivity. In combination, these data identify Tribolium as model to study genomic and gene regulatory consequences of cryptozoic adaptation.