S7-12 Monday, Jan. 6 15:00 - 15:30 Linking Genome to Phenome for Complex Traits: Studies of Global Change Adaptive Variation in Marine Invertebrates GARRETT, AD; BRENNAN, RS; STEINHART, A; PELLETIER, A; PESPENI, MH*; University of Vermont; University of Vermont; University of Vermont; University of Vermont; University of Vermont firstname.lastname@example.org http://blog.uvm.edu/mpespeni/home/
Variable environments can promote the maintenance of genetic variation that is adaptive in global change conditions. The genome of the purple sea urchin, Strongylocentrotus purpuratus, has adaptive variation that allows developing larvae to survive extreme ocean acidification conditions (pH 7.5), conditions periodically experienced in nature. However, little is known about adaptive responses to variable pH conditions or the genomic capacity to respond to future extreme low pH conditions (i.e., pH 7.0), beyond what has been experienced across space and evolutionary time. Here, we reared purple sea urchin larvae in static and variable, control and extreme acidification conditions (pH 8.1, 7.5, and 7.0) and measured survival, growth, and allele frequency shifts using pooled genomic DNA sequencing. We found decreased survival in extreme static pH conditions, with higher survival in variable conditions. In contrast, we found decreased total body length with decreasing pH, with extreme variable conditions causing the greatest decrease in larval growth. Together, these results suggest a potential tradeoff between survival and growth in extreme variable conditions. Genomic results showed consistent allele frequency shifts among replicate culture vessels with the greatest differences between pH treatments while static and variable pH treatments were most different at the lowest pH (7.0). Forthcoming analyses will reveal more about variation in the functional genetic mechanisms used to survive and grow in static versus variable and low versus extreme low pH conditions.