A genetic analysis of path length and pupation height in a natural population of Drosophila melanogaster

Abstract

Behaviour–genetic studies using laboratory strains of Drosophila are often criticized because the results cannot be generalized to natural populations. The genetic component of variation in two prepupal behaviours was studied for strains derived from a natural population of Drosophila melanogaster. These strains showed a second-chromosome based contribution to differences in path length (the distance a larva crawls in a yeasted culture dish) with the long path length phenotype dominant over the short. Differences in pupation height (the distance a larva pupates above the surface of the medium) were affected not only by the second chromosomes but also by the third pair of chromosomes. The second pair influenced the differences in pupation height threefold more than the third. Intermediate pupation heights were found in the reciprocal crosses. While path lengths could be replicated in their absolute scores over different days, pupation heights could only be replicated in their relative scores.Key words: larval behaviour, Drosophila, natural population, genetics.