Variation in Genetic Architecture of Olfactory Behavior among Wild-Derived Populations of Drosophila melanogaster

LAVAGNINO N; ANHOLT, R.R.H.; FANARA, J.J.

JOURNAL OF EVOLUTIONARY BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2008 p. 988 - 996

1010-061X

Many organisms rely on chemical cues for their survival and reproduction. Odor-guided behavior is a quantitative trait determined by many segregating genes that are sensitive to gene-gene and gene-environment interactions. Different populations are likely to experience different selection pressures on the genetic underpinnings that determine adaptive evolution of chemosensory behavior. To date, few studies have reported comparisons of the quantitative genetic basis of olfactory behavior in multiple geographically distinct populations. We generated isofemale lines of Drosophila melanogaster from six populations in Argentina and measured larval and adult responses to a standard odorant, benzaldehyde. There was significant variation within populations for both larval and adult olfactory behavior, but significant variation between populations only for larval olfactory behavior. Heritability estimates are generally low, as predicted for fitness related traits. We also found a significant genotype-by-sex interaction for adult olfactory behavior, as reported previously. However, there is substantial variation in the contribution of genotype-by-sex interaction to the total phenotypic variance among populations.  Estimates of evolvability are several orders of magnitude higher for larvae than adults across populations. Our results suggest that the potential for evolutionary adaptation to the chemosensory environment is greater at the larval survival stage than the adult reproductive stage in all populations.