Genome Wide Association Studies of early fitness traits in Drosophila melanogaster unveil plasticity and decoupling of different aspects of phenotype

PETINO ZAPPALA, M.A.; MENSCH, J.; CARREIRA, V. P.; SOTO, I.M.; FANARA, J. J.

EVOLUTIONARY BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2023

0071-3260

Great efforts have been sustained toexplain the relationships between genotype and phenotype for developmentalfitness traits through the study of their genetic architecture. However,crucial aspects of functional architecture influencing the maintenance of geneticvariability, and thus the capacity for evolutionary change, are stillunexplored. Here we performed Genome-wideAssociation Studies for phenotypic variability, plasticity and within-linecanalization at two temperatures for Larval Developmental Time (LDT), PupalDevelopmental Time (PDT), Larval Viability (LV), Pupal Viability (PV), andPupal Height (PH) in lines derived from a natural population of Drosophilamelanogaster. Results suggest changes in genetic networks linked toresource acquisition and allocation underlying variability for all traits.However, we found low genetic pleiotropy between traits and for differentaspects of phenotype (means, plasticity, within-line canalization) within eachtrait. Their genetic bases were also temperature-specific: we found no variantsshowing an effect for the same trait at both temperatures. Moreover, a geneticdecoupling between larval and pupal traits was confirmed, as there were nocandidate variants significantly associated to phenotypic variability for thesame trait across stages. We found evidence of genetic antagonistic pleiotropy forseveral loci affecting larval and pupal traits. The high degree of modularity at variouslevels would allow for the independent evolution of distinct aspects of thephenotype in different environments and ontogenetic stages. This may explainwhy genetic variation for these adaptive traits is not extinguished in naturalpopulations and may entail important implications regarding evolvability.