Meeting Abstract
S8.6 Tuesday, Jan. 6 Genetics and the nature of selection on reproductive isolation in sticklebacks BOUGHMAN, JANETTE W.; University of Wisconsin-Madison jboughman@wisc.edu
Integrating genomic and ecological approaches into the study of phenotypic evolution promises great advances in our understanding of adaptive evolution. My work combines studies of selective mechanisms with quantitative genetics and genomics to understand the forces responsible for adaptive divergence and speciation in threespine stickleback fish. We have shown previously that premating isolation in threespine sticklebacks is driven by a combination of natural and sexual selection on nuptial color and color perception, body size, and possibly body shape. With the explosion of genetic resources for threespine sticklebacks, including a complete genome sequence, we can now dig into the genetic basis of traits conferring premating isolation and adaptation to distinct environments. We focus here on the genetics of male color, which my prior work has shown to be adapted to distinct light environments in the mating habitat of two stickleback species: the limnetics and benthics. Sensory drive has contributed to divergence in color and color perception between species and appears to be a driving force in the evolution of premating isolation. We use mapping studies to identify genomic regions that underlie red or black nuptial color, and have developed an approach based on admixture mapping in a hybridizing species pair. Our mapping work reveals several genomic regions associated with red or black color. We also find that other adaptive traits co-localize to the same regions, including other traits involved in premating isolation. Genetic associations such as these should facilitate the evolution of color based premating isolation and the coevolution of male color and female color preference; they may also be generated by selection. Thus, our ongoing work combines experimental and genetic studies to investigate the nature of selection on the suite of traits that confer premating isolation.
