Meeting Abstract

66.6  Wednesday, Jan. 6  How the stickleback gets its stripes GREENWOOD, A.K.**; PEICHEL, C.L.; Fred Hutchinson Cancer Research Center, Seattle WA agreenwo@fhcrc.org

Pigment patterns exhibit striking variation in nature and are used for a diversity of functions, such as avoiding predators and attracting mates. Juvenile threespine sticklebacks from marine and freshwater populations exhibit divergent pigmentation patterns that likely provide crypsis in open water vs structured environments. Juveniles from marine environments are silver in appearance, a coloration pattern that reflects light and serves to confuse predators in an open water environment. In stark contrast, sticklebacks from freshwater lakes and streams exhibit a pattern of vertical stripes, which enables fish to blend in to a visually complex shoreline environment. We have investigated both the developmental and genetic basis of this variation. Repeated imaging of the developing pigment patterns of individual fish for two months revealed that differences in the patterning and abundance of two types of neural-crest derived pigment cells—black melanophores and silver iridophores—underlie the divergent pigment patterns. We performed genetic linkage analysis in a freshwater by marine F2 intercross to identify the genetic basis of this divergence. We identified two genomic regions underlying extent of vertical striping. We are currently using the stickleback genome assembly to identify and analyze candidate genes within these genomic regions to gain insight into the genes and pathways that are altered to yield divergent pigmentation patterns in the wild.