Temperature effects on genetic and physiological regulation of adaptive plasticity

This thesis contributed to a broader understanding of the genetic and physiological mechanisms that regulate developmental plasticity represented by butterfly wing color patterns. We found that different groups of cells within the same tissue have sensitivities and patterns of response that are distinct for the external environmental cue and for the internal hormonal signal. We also showed that the spatial compartmentalization of these responses cannot be explained by the spatial or temporal compartmentalization of the hormone receptor protein, and that manipulating pupal ecdysteroid levels is sufficient to mimic in direction and magnitude the shifts in adult reproductive resource allocation. We explored the effect of alleles of large effect on wing pattern on plasticity by characterizing thermal reaction norms for the size of eyespot rings for Bicyclus anynana mutants. Genotypes with alleles affecting eyespot size and color were the most sensitive to variation in developmental temperature. To explore genotype, temperature, and genotypextemperature effects on B. anynana development, we derived artificial selection lines expressing wet or dry-season-like phenotypes and, we characterized thermal reaction norms for a wider range of temperatures. Our results provided evidence for significant GxE effects, and also revealed a possible new color appearing at the most extreme low temperatures.