Population dynamics of the 2 major mitochondrial DNA haplotypes in experimental populations of Drosophila subobscura

• Published in: Genome Vol. 48; no. 6; pp. 1010 - 1018
• Main Authors: Oliver, Pedro, Balanyà, Joan, Ramon, Maria Misericòrdia, Picornell, Antònia, Serra, Lluis, Moya, Andrés, Castro, José A
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.12.2005; Canadian Science Publishing NRC Research Press
• Subjects: Animals; Chromosomes; DNA, Mitochondrial - genetics; Drosophila - genetics; Drosophila subobscura; Female; Fertility; Genetic Drift; Genomics; Geographical distribution; Haplotypes; Insects; Life history; Male; Mitochondria - genetics; Mitochondrial DNA; Natural populations; Population Dynamics; Selection, Genetic; Spain, Balearic Is., Majorca
• ISSN: 0831-2796; 1480-3321
• DOI: 10.1139/g05-077

The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Calvià (Majorca, Balearic Islands, Spain). This population, like others founded in Europe, is characterized by the presence of 2 very common (>95%) mitochondrial haplotypes (named I and II) and rare and endemic haplotypes that appear at very low frequencies. Four experimental populations were established with flies having a heterogeneous nuclear genetic background, which was representative of the composition of the natural population. The populations were started with haplotypes I and II at an initial frequency of 50% each. After 33 generations, the 2 haplotypes coexisted. Random drift could be rejected as the only force responsible for the observed changes in haplotype frequencies. A slight but significant linear trend favouring a mtDNA (haploid) fitness effect has been detected, with a nonlinear deviation that could be due to a nuclear component. An analysis of chromosomal arrangements was made before the foundations of the cages and at generation 23. Our results indicated that the hypothesis that the maintenance of the frequencies of haplotypes I and II in natural populations could be due to their association with chromosomal arrangements remains controversial.Key words: natural selection, random drift, cytonuclear interactions, chromosomal arrangements, mtDNA haplotypes, Drosophila subobscura.