Genetic structure and gene flow of Anopheles minimus and Anopheles harrisoni in Kanchanaburi Province, Thailand

Abstract

Isozyme frequencies were compared in seven field collections of Anopheles minimus complex using starch gel electrophoresis. Mosquito collections were sampled from four districts in Kanchanaburi Province where malaria is endemic. From eight enzyme systems, nine loci and seven polymorphisms were detected, indicating limited genetic differentiation among the seven collections (F(ST) = 0.061). The highest percent polymorphic loci were observed in Bong Ti Noi (BTN) Village (55.6%), whereas the least percent polymorphism was seen in Tha Kradan (TK) Village (22.2%). Comparing villages Pra Jedee (PJ) with Pu Teuy C (PTC) and Huai Khayeng (HK) with Pra Jedee (PJ), gene flow among collections varied from 3.72 to 62.25 reproductive migrants per generation. Among the seven collections, no correlation was seen between genetic and geographical distances (P > 0.05). Anopheles minimus (former species A) and Anopheles harrisoni (former species C) from Pu Teuy fit most closely in the same cluster, possibly indicating relatively recent divergence between taxa. The genetic and epidemiological ramifications of these findings are discussed.

Diversity of Anopheles species and trophic behavior of putative malaria vectors in two malaria endemic areas of northwestern Thailand

“…Unfortunately, most of these observations relied on species that were identified by morphological characters alone, as molecular assays capable of reliably identifying each sibling species were not readily available or still non‐existent. During the past few decades, studies on malaria vectors in Thailand using molecular identification assays have increased and provided precise identification to the species level, as well as the recognition of additional Anopheles species and species complexes in Thailand (Baimai et al , , Baimai , Green et al , Green et al , Poopittayasataporn and Baimai , Walton et al , Garros et al , Rattanarithikul et al , Dusfour et al , Walton et al , Poolprasert et al , Saeung et al , Thongsahuan et al , Eamkum et al ).…”

Multilocus nuclear DNA markers reveal population structure and demography of Anopheles minimus

“…Similarly, the Pu Teuy region (Kanchanaburi Province) of Thailand, which was earlier free of An. minimus, has recently reported the presence of this species (Poolprasert et al 2008). Based on the adaptability of this species to different eco-climatic conditions, it is of interest to understand population structure and demographic history of An.…”

“…Furthermore, considering An. minimus as highly invasive in India (Jambulingam et al 2005) and in Thailand (Poolprasert et al 2008) with evidence of population structure Morgan et al 2011), different models of population demography could be tested with the high-resolution putatively neutral multilocus DNA markers (Das et al 2004;Dixit et al 2011;Gupta et al 2012). We therefore have utilized seven of the eight previously developed markers in the X chromosome of An.…”

Genetic diversity and differentiation between Palearctic and Nearctic populations ofAedimorphus (=Aedes) vexans(Meigen, 1830) (Diptera, Culicidae)

“…The study of intra‐ and inter‐population genetic diversity provides insights into epidemiologically important species influenced by evolutionary factors, including gene flow and different selection regimes (Poolprasert et al 2008). In addition, genetic variation provides raw material for change within populations that are subjected to new pressures, especially anthropogenic changes in environment such as insecticide application (Paupy et al 2005).…”

“…Since genetic variation can represent the potential to respond to the selection pressures of insecticides (Paupy et al 2005), genetic diversity is thought to have implications for vector control programs (Tabachnick and Black 1995, Singh et al 2004). Indeed, genetic diversity has been used for defining vector capacity of the epidemiologically important species (Poolprasert et al 2008). Hence, the study of the adaptive capacity of a vector of human and animal disease to rapid ecological change is important to public health (Patz et al 2000, Manguin and Boëte 2011, Tabachnick 2010).…”