Mitochondrial DNA (mtDNA) has been one of the most extensively studied molecules Lite-Plan PRA Emergency Inverters in ecological, evolutionary and clinical genetics.In its early application in evolutionary genetics, mtDNA was assumed to be a selectively neutral marker conferring negligible fitness consequences for its host.However, this dogma has been overturned in recent years due to now extensive evidence for non-neutral evolutionary dynamics.Since mtDNA proteins physically interact with nuclear proteins to provide the mitochondrial machinery for aerobic ATP production, among other cell functions, co-variation of the respective genes is predicted to affect organismal fitness.
To test this hypothesis we used an mtDNA-nuclear DNA introgression model in Drosophila melanogaster to test the fitness of genotypes in perturbation-reperturbation population cages and in a non-competitive assay for female fecundity.Genotypes consisted of both conspecific and heterospecific mtDNA-nDNA constructs, with either D.melanogaster or D.simulans mtDNAs on two alternative D.
melanogaster nuclear backgrounds, to investigate mitonuclear genetic interactions (G x G effects).We found considerable variation between nuclear genetic backgrounds on the selection of mtDNA haplotypes.In addition, there was variation in the selection on mtDNAs pre- and post- reperturbation, demonstrating overall poor repeatability of selection.There was a strong influence of nuclear background on non-competitive fecundity across all the mtDNA species types.
In only one of the four cage types did we see a significant fecundity effect between genotypes that could help explain the respective change in genotype frequency over generational time.We discuss these results in the context of G x G interactions and the possible influence of stochastic Fabric Refreshers environments on mtDNA-nDNA selection.