Masters Degrees (Genetics)

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Browsing Masters Degrees (Genetics) by Author "Du Toit, Zelda"

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    Population genetic structure of the ground pangolin based on mitochondrial genomes
    (University of the Free State, 2014-03) Du Toit, Zelda; Grobler, J. P.; Kotzé, A.; Dalton, D. L.
    English: Temminck’s ground pangolin, S. temminckii, is currently listed as Vulnerable on the IUCN Red Data List. However, their numbers are decreasing due to illegal hunting for bush meat and over-harvesting for traditional use in Africa. Pangolins are also exported to Asia as a delicacy and for use in traditional medicine. Currently, the greatest threat to ground pangolins in southern Africa is electrocution by electric fences on game farms. This project consisted of two parts. The first was to sequence the whole mtDNA genome of Temminck’s ground pangolin to identify gene regions and to determine the evolutionary relationship of the order Pholidota. Results generated using the primer walking method, indicated that the whole mtDNA of Temminck’s ground pangolin is 16,559 bp in length. The phylogenetic analysis shows that the order Pholidota form a sister grouping with the order Carnivora rather than with the order Xenarthra as would be expected. Data suggested a Laurasian origin approximately 87 mya and possible migration into Africa during the Paleocene era around 55 mya. The second part of the study was conducted in order to determine the phylogeography of Temminck’s ground pangolins in southern Africa. Twenty five samples were collected from four countries, namely Namibia, Zimbabwe, Mozambique and South Africa (Mpumalanga and the Northern Cape Provinces). The results obtained indicated a high level of genetic variation within populations and only a few individuals displayed private haplotypes, which resulted in an increase in haplotype diversity. Samples from Zimbabwe and Mozambique (Group 1) clustered together while samples from the Northern Cape and Mpumalanga Provinces of South Africa grouped with samples from Namibia (Group 2), suggesting either an ancestral or recent split between Groups 1 and 2. The BEAST analysis indicated that the two groups shared a recent common ancestor between 2.94 and 1.27 mya across the three gene regions. In addition, it was estimated that the Zimbabwe/Mozambique split occurred between 920 and 710 kya and the Kalahari/Namibia/Mpumalanga split between 1.16 mya and 790 kya. This pattern corresponds to the Mega Kalahari Sand Sea forming a barrier between individuals and populations around that time. This study is the first molecular analysis based on the mitochondrial DNA genome of Temminck’s ground pangolin in southern Africa and it provides an insight into the species’ population genetics across its range in southern Africa. However, additional research into the order Pholidota throughout Africa can assist in better understanding of genetic variation within African pangolin species and populations. Furthermore, such studies will also support the conservation of genetic variation within species and contribute to identifying evolutionary distinct populations to assist in developing effective conservation management plans for the different species of the order Pholidota.