Genetic basis of phenotypic variation and plasticity in developmental adaptive traits of Drosophila melanogaster.

PETINO ZAPPALA, A; MENSCH, J; SOTO, I; CARREIRA, V.; ORTIZ, V; SATORRE; FANARA, J.J.

Montevideo

Congreso; VI International Meeting of the Latin American Society for Developmental Biology; 2012

Latin American Society for Developmental Biology

In order to study the genetic basis of phenotypic variability in adaptive traits in Drosophila melanogaster, a reference panel of isogenic lines was created. All lines were derived from a natural population and their nuclear genomes were completely sequenced. This genetic system allows the identification of Quantitative Trait Loci (QTLs) and Single Nucleotide Polimorphisms (SNPs) which determine phenotypic variability and plasticity for any trait of interest. Here we present the analysis of candidate QTLs affecting Developmental Time (decomposed in larval and pupal DT), pupation height and viability of immature stages, measured in flies reared at low and optimal temperatures. This allowed us to find also candidate QTLs which influence developmental plasticity in these traits. We observed a strong positive correlation between total DT and larval DT for each temperature, but not between total DT and pupal DT. This decoupling was also observed between viability for larval and pupal stages. For each temperature, viability of the larval stage showed a negative correlation with DT and a positive correlation with pupation height. No correlations were found for any given trait between both temperatures (excepting for pupation height). Although we found pervasive genotype x temperature interaction for all traits, genetic correlations between characters were not affected by temperature.  As expected, we found stage-specific and temperature-specific loci, as well as loci which affect developmental traits in both stages or temperatures. Further analysis of D. melanogaster lines derived from other natural populations will determine if these QTLs are also responsible for phenotypic variation and plasticity in the traits studied, and how the SNPs vary in relation to the environment of origin.