Competition between Mitochondrial Haplotypes in Distinct Nuclear Genetic Environments: Drosophila Pseudoobscura Vs. D. Persimilis
AUTOR(ES)
Hutter, C. M.
RESUMO
A test for coadaptation of nuclear and mitochondrial genomes was performed using the sibling species, Drosophila pseudoobscura and D. persimilis. Two lines of flies with ``disrupted'' cytonuclear genotypes were constructed by repeated backcrossing of males from one species to females carrying mitochondrial DNA (mtDNA) from the other species. Each ``disrupted'' strain was competed in population cages with the original stock of each species from which the recurrent males were obtained during the backcrossing. As such, the two species' mitochondrial types were competed reciprocally in the nuclear genetic environments of each species. The trajectories of mtDNA haplotypes were followed in discrete-generation population cages using a PCR-four-cutter approach. A significant increase in the frequency of D. pseudoobscura mtDNA was observed in each of four replicate cages with a D. pseudoobscura nuclear background. In the D. persimilis nuclear background, one cage actually showed an increase in frequency of D. pseudoobscura mtDNA, although together the four replicate cages show little change in frequency. These results were repeated after frequency perturbations and reinitiation of each cage. An analysis of fitness components revealed that fertility selection greatly outweighed viability selection in these cytonuclear competition experiments. The asymmetry of the fitnesses of the mtDNA haplotypes on the two genetic backgrounds is consistent in direction with the previously reported asymmetry of female fertility in backcrosses between these two species. While our experiments do not allow us to identify mtDNA as the sole source of fitness variation, at a minimum the data indicate a fitness association between nuclear fertility factors and the D. pseudoobscura mtDNA on its own genetic background.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1206633Documentos Relacionados
- A Comparative Study of the Esterase-5 Locus in DROSOPHILA PSEUDOOBSCURA, D. PERSIMILIS and D. MIRANDA
- Variation in Activities of Amylase Allozymes Associated with Chromosome Inversions in DROSOPHILA PSEUDOOBSCURA, D. PERSIMILIS and D. MIRANDA
- Genetics of Male and Female Sterility in Hybrids of Drosophila pseudoobscura and D. persimilis
- Little qualitative RNA misexpression in sterile male F1 hybrids of Drosophila pseudoobscura and D. persimilis
- Evidence for Extensive Genetic Differentiation between the Sex-Ratio and the Standard Arrangement of DROSOPHILA PSEUDOOBSCURA and D. PERSIMILIS and Identification of Hybrid Sterility Factors