Drosophila simulans strain:Nueva Phenotype or Genotype. Drosophila simulans strain:Nueva

The goal of our project was to identify the genetic basis for ecological specialization. The fruit fly Drosophila sechellia is a specialist that utilizes a single resource, the fruit of Morinda citrifolia, which is toxic to other species of the melanogaster subgroup when it is ripe. Crosses between D. sechellia and its sibling species,D. simulans produce fertile female offspring, allows a genetic approach. We use multiplexed shotgun genotyping and high resolution QTL analysis to examine the genetic basis of resistance to M. citrifolia fruit toxin. We find that at least four dominant and four recessive loci interact additively to confer resistance to the M. citrifolia fruit toxin. We identify a dominant locus of large effect on the third chromosome (QTL-IIIsima) that was not detected in previous analyses. The identification of QTL-IIIsima, here, is an important step towards identifying the molecular basis of specialization upon M. citrifolia fruit by D. sechellia.