Mathematical Biology Seminar Mike Shapiro Biology Department, University of Utah Wednesday October 25, 2006 3:05pm in LCB 215 "Genetic and developmental basis of pelvic reduction in stickleback fish" Abstract: A fundamental question in studies of parallel evolution is whether the same gene or genes control similar adaptive phenotypes in different populations and species. Sticklebacks provide numerous opportunities to study the genetic basis of parallel evolution. In particular, threespine (Gasterosteus aculeatus) and ninespine (Pungitius pungitius) sticklebacks show repeated evolution of similar adaptive traits among different populations within each genus, and these two genera also have evolved similar derived traits in parallel. Through intergeneric complementation tests, we demonstrated that at least one adaptive trait, pelvic reduction, likely evolved by similar genetic mechanisms in specific populations of both genera. To examine the genetic architecture of other interesting traits in Pungitius, we generated new genetic and genomic resources, including the first genome-wide linkage map for the ninespine stickleback. Genetic mapping studies revealed that sex determination in ninespine sticklebacks and threespine sticklebacks are controlled by different chromosome regions, and we identified a second region that plays a major role in pelvic reduction. Further studies using genetic and genomic resources from both genera will allow us to directly compare the chromosomal location and genetic architecture of other interesting, adaptive traits that evolved in parallel in these taxa.