Natural variability in Drosophila larval and pupal NaCl tolerance

[Display omitted] •Drosophila melanogaster lines were selected for very high salt tolerance.•Salt-tolerant lines grow and survive better than controls when reared on salty media.•Choice of pupation position is also correlated with the degree of salt-tolerance.•QTL for larval and pupal salt tolerance were found using recombinant inbred lines.•Pupal and larval salt tolerance is uncorrelated and each trait has distinct QTL. The regulation of NaCl is essential for the maintenance of cellular tonicity and functionality, and excessive salt exposure has many adverse effects. The fruit fly, Drosophila melanogaster, is a good osmoregulator and some strains can survive on media with very low or high NaCl content. Previous analyses of mutant alleles have implicated various stress signaling cascades in NaCl sensitivity or tolerance; however, the genes influencing natural variability of NaCl tolerance remain for the most part unknown. Here, we use two approaches to investigate natural variation in D. melanogaster NaCl tolerance. We describe four D. melanogaster lines that were selected for different degrees of NaCl tolerance, and present data on their survival, development, and pupation position when raised on varying NaCl concentrations. After finding evidence for natural variation in salt tolerance, we present the results of Quantitative Trait Loci (QTL) mapping of natural variation in larval and pupal NaCl tolerance, and identify different genomic regions associated with NaCl tolerance during larval and pupal development.