open access

https://hdl.handle.net/2115/75466

Genetic diversity and population structure of Glossina morsitans morsitans in the active foci of human African trypanosomiasis in Zambia and Malawi

英語

2019-07-25

Public Library of Science

PLoS neglected tropical diseases

13(7)

e0007568

The tsetse fly, Glossina morsitans morsitans, is a significant problem in Zambia and Malawi. It is the vector for the human infective parasite Trypanosoma brucei rhodesiense, which causes human African trypanosomiasis, and various Trypanosoma species, which cause African animal trypanosomiasis. Understanding the genetic diversity and population structure of G. m. morsitans is the basis of elucidating the connectivity of the tsetse fly populations, information that is essential in implementing successful tsetse fly control activities. This study conducted a population genetic study using partial mitochondrial cytochrome oxidase gene 1 (CO1) and 10 microsatellite loci to investigate the genetic diversity and population structure of G. m. morsitans captured in the major HAT foci in Zambia and Malawi. We have included 108 and 99 G. m. morsitans samples for CO1 and microsatellite analyses respectively. Our results suggest the presence of two different genetic clusters of G. m. morsitans, existing East and West of the escarpment of the Great Rift Valley. We have also revealed genetic similarity between the G. m. morsitans in Kasungu National Park and those in the Luangwa river basin in Zambia, indicating that this population should also be included in this historical tsetse belt. Although further investigation is necessary to illustrate the whole picture in East and Southern Africa, this study has extended our knowledge of the population structure of G. m. morsitans in Southern Africa. Author summary Techniques from population genetics have been widely applied to assess problems in evolutionary biology, computational biology, wildlife conservation, animal breeding, etc. In this study, we used population genetics approaches to elucidate the genetic population structure of the tsetse fly Glossina morsitans morsitans, an important vector of the Trypanosoma parasite. Our aim was to identify the optimal range of areas in which to implement effective tsetse fly control programs. We focused on five areas of active human African trypanosomiasis foci in Zambia and Malawi and used both mitochondrial and nuclear markers for population genetics analyses. High levels of genetic differentiation were observed between G. m. morsitans in Nkhotakota Wildlife Reserve, Malawi, and those at the other locations included in this study. Nkhotakota Wildlife Reserve lies on the eastern side of the escarpment of the Great Rift Valley at an altitude that is at the biological limit of G. m. morsitans, thereby functioning as a geographical barrier restricting gene flow from the G. m. morsitans on the western side of the escarpment. The western side of the escarpment is part of a historically-known tsetse belt that resides within the Luangwa river basin. We have demonstrated that a previously undescribed population of G. m. morsitans in Kasungu National Park, Malawi, should be included in this historical tsetse belt.

学術雑誌論文

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Creative Commons Attribution 4.0 International

1935-2727

1935-2735