Whole genome sequencing of Drosophila ananassae population pools
As a major element of the environment, temperature impacts the geographical ranges of insects. Therefore, the worldwide distribution of insects follows adaptation to wide ranges of temperature. A population of Drosophila ananassae from the ancestral region showed variation in cold tolerance levels. The ancestral Bangkok population also differed from the derived Kathmandu population regarding cold tolerance. However, the phenotypic variation was only measured by chill coma assays, and no further characterization of the cold tolerance phenotype was performed. Here, we aimed to characterize further the iso-female lines of Bangkok and Kathmandu populations and the recombinant inbred lines generated from the ancestral population using lethal time and cold shock mortality in addition to chill coma recovery time. We performed bulk segregant analysis using the recombinant inbred lines that exhibited extreme chill coma recovery time to identify genomic regions responsible for the phenotype.The study uses pools of individuals (from recombinant inbred lines) that exhibit extreme cold tolerance phenotypes (chill coma recovery time) compared to the founder strains of Drosophila ananassae. This experimental setup serves the purpose of identifying the genomic regions associated with the tested cold tolerance phenotype. It sheds light on the genetic architecture of adaptive phenotypic changes in natural populations of Drosophila.