title: The Effect of Temperature onDrosophilaHybrid Fitness.
abstract: Mechanisms of reproductive isolation inhibit gene flow between species and can be broadly sorted into two categories: prezygotic and postzygotic. While comparative studies suggest that prezygotic barriers tend to evolve first, postzygotic barriers are crucial for maintaining species boundaries and impeding gene flow that might otherwise cause incipient species to merge. Most, but not all, postzygotic barriers result from genetic incompatibilities between two or more loci from different species, and occur due to divergent evolution in allopatry. Hybrid defects result from improper allelic interactions between these loci. While some postzygotic barriers are environmentally-independent, the magnitude of others has been shown to vary in penetrance depending on environmental factors. We crossedDrosophila melanogastermutants to two other species,D. simulansandD. santomea, and collected fitness data of the hybrids at two different temperatures. Our goal was to examine the effect of temperature on recessive incompatibility alleles in their genomes. We found that temperature has a stronger effect on the penetrance of recessive incompatibility alleles in theD. simulansgenome than on those in theD. santomeagenome. These results suggest that the penetrance of hybrid incompatibilities can be strongly affected by environmental context, and that the magnitude of such gene-by-environment interactions can be contingent on the genotype of the hybrid.
authors.affiliation: Biology Department, University of North Carolina, Chapel Hill, North Carolina 27510.
authors.forename: Charles J J
authors.initials: CJ
authors.lastname: Miller
authors.affiliation: Biology Department, University of North Carolina, Chapel Hill, North Carolina 27510 dmatute@email.unc.edu.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Matute
mesh_terms: D000483:Alleles; D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004331:Drosophila melanogaster / Q000235:genetics*; D000067636:Drosophila simulans / Q000235:genetics; D059647:Gene-Environment Interaction; D056084:Genetic Fitness / Q000235:genetics / Q000502:physiology; D006824:Hybridization, Genetic; D060047:Reproductive Isolation; D013696:Temperature
keywords: Drosophila; hybrids; postzygotic isolation; temperature