Mitochondrial DNA variation in the malaria vector Anopheles minimus across China, Thailand and Vietnam: evolutionary hypothesis, population structure and population history

Abstract

The effects of Pleistocene environmental fluctuations on the distribution and diversity of organisms in Southeast Asia are much less well known than in Europe and North America. In these regions, the combination of palaeoenvironmental reconstruction and inferences about population history from genetic data has been very powerful. In Southeast Asia, mosquitoes are good candidates for the genetic approach, with the added benefit that understanding the relative contributions of historical and current processes to population structure can inform management of vector species. Genetic variation among populations of Anopheles minimus was examined using 144 mtDNA COII sequences from 23 sites in China, Thailand and Vietnam. Haplotype diversity was high, with two distinct lineages that have a sequence divergence of over 2% and exhibit different geographical distributions. We compare alternative hypotheses concerning the origin of this pattern. The observed data deviate from the expectations based on a singlepanmictic population with or without growth, or a stable but spatially structured population. However, they can be readily accommodated by a model of past fragmentation into eastern and western refugia, followed by growth and range expansion. This is consistent with the palaeoenvironmental reconstructions currently available for the region.

Glacial History of a Modern Invader: Phylogeography and Species Distribution Modelling of the Asian Tiger Mosquito Aedes albopictus

“…albopictus populations [74]. We found not only a non-negligible genetic diversity–within the range of that observed in other mosquito species uninfected by Wolbachia [26], [48], [81]–but also an overall concordance between the genetic patterns observed at nuclear and mitochondrial markers; this would not be expected if mtDNA selective sweep had occurred [82]. Previous population genetics studies conducted using allozymes showed significant genetic differentiation between populations at a regional level, but a lack of discontinuity in the geographic distribution of genetic diversity at the level of mainland Asia as a whole [41], [42], [83].…”

Local Adaptation along Smooth Ecological Gradients Causes Phylogeographic Breaks and Phenotypic Clustering

“…One particularly notable result is that selectiondriven phylogeographic structure tends to increase with increasing population size. Many studies have discounted the possibility that phylogeographic breaks arise without geographic barriers because the species under study have large populations (e.g., Chen et al 2011), but the results here show that species with large populations may be particularly likely to show phylogeographic structure when it is driven in part by selection.…”

Population genetics of the malaria vector Anopheles aconitus in China and Southeast Asia

“…In particular, the mitochondrial cytochrome oxidase II gene ( COII ) has been successfully used to study population genetic structure and population history for a wide range of insect species (Krafsur et al, 1999; Sperling et al, 1999; Clements et al, 2000; Franck et al, 2001; Rua et al, 2001; Chen et al, 2004; Chen et al, 2011). In the present study, we sampled populations of An.…”