Adaptive significance of amylase polymorphism in drosophila. XV.: Examination of genotype-by-environment interactions on the viability, developmental time and stability of drosophila subobscura homozygous for amy during exposure to nutritional changes

Abstract

Due to the direct interaction between enzyme and substrate, the amylase system can provide valuable information on the relationship between homozygosity and developmental homeostasis under a changing environment in several Drosophila species, The adaptive significance of the relationship between genetic variability and environmental change manifests through the well-known polymorphism of the amylase locus (Amy). We examined the effect of gradual and abrupt changes in starch concentration in the nutritional substrate, on the developmental time, egg-to-adult viability and phenotypic plasticity in the progeny of Drosophila subobscura that was homozygous for "fast" (Amy F/Amy F) and "slow" (Amy S/Amy S) Amy alleles. Our findings show that gradual and abrupt nutritional changes exert a significant effect on developmental time and viability. A high heterogeneity among genotypes in fluctuating asymmetry (FA) and no direct association between FA and fitness components under the two experimental regimes of environmental change were observed.