Meeting Abstract
P3.30 Thursday, Jan. 6 Temperature-dependent Sex Determination: Merging Classical Genetics and Next Generation Sequencing Technologies to Identify Temperature Sensitive Genes RHEN, Turk*; SCHROEDER, Anthony; LEVIN, June; FAGERLIE, Ruby; LEGGE, Heath; WESSMAN, Laurel; University of North Dakota turk.rhen@und.nodak.edu
Temperature-dependent sex determination (TSD) is found in many vertebrates, including some fish and amphibians, several lizards, tuatara, numerous turtles, and all crocodilians. However, the gene (or genes) that transduces temperature into a biological signal for ovary versus testis development is not known in any species. We are using three complementary approaches to dissect the molecular basis for TSD in the common snapping turtle, Chelydra serpentina. For the first study, we used “next generation” sequencing for de novo characterization of the transcriptome in gonads from turtle embryos incubated under male and female thermal regimes. We are using this data to identify transcripts that are differentially expressed in incipient testes and ovaries during the thermosensitive period and to detect sequence polymorphisms that will be used in genetic association studies. For the second study, we established a captive breeding colony of adult snapping turtles to dissect and quantify additive genetic variation, variation due to genes that display dominance, and non-genetic maternal effects on sex determination at incubation temperatures that produce mixed sex ratios. Finally, we will use allele specific expression assays and standard quantitative PCR to analyze genetic variation in gene expression profiles in a subset of embryos from the second study. All of this data will be combined to develop explicit models of the gene regulatory network underlying temperature-dependent development of testes versus ovaries. Here we report results of our transcriptome analyses and describe the origin of our breeding colony. We wish to make this living resource and our “genetical genomics” approach available to researchers studying other aspects of turtle biology.
