Divergent evolution of molecular markers during laboratory adaptation in Drosophila subobscura

Abstract

The impact of genetic drift in population divergence can be elucidated using replicated laboratory experiments. In the present study we used microsatellite loci to study the genetic variability and differentiation of laboratory populations of Drosophila subobscura derived from a common ancestral natural population after 49 generations in the laboratory. We found substantial genetic variability in all our populations. The high levels of genetic variability, similar across replicated populations, suggest that careful maintenance procedures can efficiently reduce the loss of genetic variability in captive populations undergoing adaptation, even without applying active management procedures with conservation purposes, in organisms that generate a high number of offspring such as Drosophila. Nevertheless, there was a significant genetic differentiation between replicated populations. This shows the importance of genetic drift, acting through changes in allele frequencies among populations, even when major changes in the degree of genetic diversity in each population are not involved.

Host Association of Spodoptera frugiperda (Lepidoptera: Noctuidae) Corn and Rice Strains in Argentina, Brazil, and Paraguay

“…Although we assume that our laboratory populations represent the mitochondrial haplotypes of wild populations, there is a possible effect of homogenization as a result of our laboratory rearing (Berlocher and Friedman 1981;Simõ es et al 2008Simõ es et al , 2010. To avoid this, we collected a large number of individuals from wild populations that were used to establish the colonies, and the material for DNA extraction was obtained from the very Þrst generations in culture.…”

From nature to the laboratory: the impact of founder effects on adaptation

“…Dlugosch & Parker () also saw this general tendency when compiling information on several founding events. Genetic drift due to reduced effective population size was the major force causing this loss of variability, and its effects changed through time, being stronger in the early phases of evolution after the founding event, reinforcing the conclusions of our previous studies (Simões et al ., , ). As expected, this effect was particularly strong for allelic richness (Fig.…”

Development of a Nasonia vitripennis outbred laboratory population for genetic analysis

“…; Frankham ; Simoes et al . ). While effective population size is influenced by many factors, such as fluctuations in population size over generations, variation in family size and sex ratio, mating system and selection, work by Simoes et al .…”

“…While effective population size is influenced by many factors, such as fluctuations in population size over generations, variation in family size and sex ratio, mating system and selection, work by Simoes et al . () has shown that careful maintenance procedures can efficiently reduce the loss of genetic variability in laboratory populations in organisms that generate a high number of offspring. The results described here for the HVRx population corroborate this finding.…”