0000000000385075
AUTHOR
John S. Christie
Assortative mating and fertility in two Drosophila subobscura strains with different mitochondrial DNA haplotypes.
The mating pattern and female fertility on the two main mitochondrial DNA haplotypes (I and II) of Drosophila subobscura were studied, in an attempt to find possible differences between them in relation to sexual selection or isolation that could explain the populational dynamics and the co-existence of these two strains in nature. The mating pattern indicated an assortative mating in population cages, where couples of the same haplotype, mainly those of haplotype I, mated more often. However, the significations detected in laboratory conditions disappeared in wild populations, where random mating was the rule. The female fertility also showed differences in the laboratory compared to the w…
Fitness and life-history traits of the two major mitochondrial DNA haplotypes of Drosophila subobscura
Mitochondrial DNA restriction site analyses on natural populations of Drosophila subobscura have proved the existence of two common, coexisting haplotypes (I and II), as well as a set of less frequent ones derived from them. To explain this distribution, experiments to date point practically to all possible genetic mechanisms being involved in the changes of gene frequencies (cytonuclear coadaptation, direct natural selection on mtDNA and genetic drift). In an attempt to find differences that help to understand the dynamics of these haplotypes and to detect the effect of selection, we measured certain fitness components and life-history traits (egg-larva and larva-adult viabilities and deve…
Mitochondrial DNA effects on fitness in Drosophila subobscura
We tested different fitness components on a series of conspecific mtDNA haplotypes, detected by RFLPs in Drosophila subobscura. Additionally, haplotype VIII, endemic to the Canary Islands, was tested upon its own native nuclear DNA background and upon that of the rest of mtDNAs tested herein. We found that both nuclear and mitochondrial DNA can have a significant effect upon their hosts' fitness, and that negative selection is one of the mechanisms that can intervene in this species' mtDNA haplotype pattern. We discuss the importance of this mechanism in relation to genetic drift, in the form of periodic population bottlenecks, and how the latter can enhance the former. We also detected a s…