Term of Award

Summer 2013

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Department

Department of Biology

Committee Chair

Lorenza Beati Ziegler

Committee Member 1

Lance A. Durden

Committee Member 2

Oscar Pung

Abstract

The tick genus Amblyomma includes approximately 130 species, 28 of which are found on the African continent and/ or in Madagascar. In order to understand the evolutionary phylogeography of the genus, it is necessary to gain a better understanding of the relationships between African taxa. Therefore, the main goals of this work were to, (1) reconstruct the phylogenetic relationships of the African Amblyomma available to us and (2) test markers for their usefulness as barcoding tools to link unknown immature specimens to their corresponding adults. The mitochondrial gene markers used in this study (12SrDNA and COI) did not resolve the phylogeny of the studied taxa at all hierarchical levels. Nevertheless, they were informative in resolving recent diverging events between closely related species and at the intraspecific level. They also proved to be promising in terms of “DNA barcoding” and allowed us to identify a number of previously non-identified immature specimens. Combined datasets showed that the former genus Aponomma is basal to Amblyomma. Also, reptile or bird feeding species were basal in the tree, intermediate lineages were associated with typical Afro-Asian mammals (elephant, rhinoceros and pangolin), and the most recently evolving taxa were associated with wild and domestic ungulates which are thought to have reached Africa more recently. Amblyomma sparsum and A. nuttalli were consistently grouped as sister taxa as were A. cohaerens and A. splendidum. This information is critical in that it helps us to have a better understanding of the phylogeographical patterns associated with a genus that has a typical Gondwana distribution. It is also beneficial to develop adequate epidemiological prevention strategies as it can influence the distribution of African Amblyomma tick species within and outside of Africa. It can also influence the rates and control of Amblyomma transmitted diseases in animals and humans.

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