Genetic diversity and interspecies hybridization in Cossypha robin-chats

A dissertation submitted to the Faculty of Science University of the Witwatersrand Johannesburg, South Africa in fulfilment of the requirements for the degree of Master of Science. June 2017 === Southern Africa boasts a high avian diversity with five Cossypha (robin-chat) species (C. heuglini,...

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Main Author: Munshi, Naadhirah
Format: Others
Language:en
Published: 2017
Subjects:
Online Access:Munshi, Naadhirah (2017) Genetic diversity and interspecies hybridization in cossypha robin-chats, University of the Witwatersrand, Johannesburg, <http://hdl.handle.net/10539/23464>
http://hdl.handle.net/10539/23464
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spelling ndltd-netd.ac.za-oai-union.ndltd.org-wits-oai-wiredspace.wits.ac.za-10539-234642019-05-11T03:40:46Z Genetic diversity and interspecies hybridization in Cossypha robin-chats Munshi, Naadhirah Hybridization Birds A dissertation submitted to the Faculty of Science University of the Witwatersrand Johannesburg, South Africa in fulfilment of the requirements for the degree of Master of Science. June 2017 Southern Africa boasts a high avian diversity with five Cossypha (robin-chat) species (C. heuglini, C. caffra, C. humeralis, C. natalensis, C. dichroa) distributed at varying levels of sympatry and allopatry. Due to the effects of global anthropogenic change many species which were once ecologically separated may now overlap, leading to possible genetic introgression and hybridization. This project investigates the genetic diversity and degree of relatedness between the five Cossypha robin-chat species that occur in South Africa. Genomic DNA was extracted from blood of all five species (n=92 individuals) using the standard phenol:chloroform extraction method. Mitochondrial and nuclear markers were analyzed using Likelihood and Bayesian methods to establish phylogenetic relationships and to determine speciation patterns. MtDNA barcoding using the cytochrome c oxidase subunit 1 (CO1) gene was used to assign individuals to species. The construction of a neighbour-joining and a maximum likelihood tree provided graphic representations of the pattern of divergences between the five Cossypha species. Individuals from a species clustered together with strong bootstrap values. These procedures were accomplished using MEGA software. PopART was used to construct a minimum spanning network. This network illustrated similarity between the five species with regards to the CO1 barcode. Only seven of thirteen novel microsatellite markers were able to cross amplify in all five species. The Bayesian clustering analysis using the statistical programme STRUCTURE identified three genetic clusters (K=3) with the three distinct species being C. dichroa, C. natalensis, and C. caffra. Cossypha heuglini cluster amongst C. dichroa, C. natalensis, and C. caffra, while C. humeralis clusters amongst C. natalensis. Despite the hybridization events recorded between C. dichroa and C. natalensis these two species do not appear to be each other’s closest relatives according to microsatellite and mtDNA analysis. The hybridization events indicate their ability to overcome reproductive isolation mechanisms such as vocalisations. MT 2017 2017-12-07T13:37:37Z 2017-12-07T13:37:37Z 2017 Thesis Munshi, Naadhirah (2017) Genetic diversity and interspecies hybridization in cossypha robin-chats, University of the Witwatersrand, Johannesburg, <http://hdl.handle.net/10539/23464> http://hdl.handle.net/10539/23464 en Online resource (xii, 71 leaves) application/pdf
collection NDLTD
language en
format Others
sources NDLTD
topic Hybridization
Birds
spellingShingle Hybridization
Birds
Munshi, Naadhirah
Genetic diversity and interspecies hybridization in Cossypha robin-chats
description A dissertation submitted to the Faculty of Science University of the Witwatersrand Johannesburg, South Africa in fulfilment of the requirements for the degree of Master of Science. June 2017 === Southern Africa boasts a high avian diversity with five Cossypha (robin-chat) species (C. heuglini, C. caffra, C. humeralis, C. natalensis, C. dichroa) distributed at varying levels of sympatry and allopatry. Due to the effects of global anthropogenic change many species which were once ecologically separated may now overlap, leading to possible genetic introgression and hybridization. This project investigates the genetic diversity and degree of relatedness between the five Cossypha robin-chat species that occur in South Africa. Genomic DNA was extracted from blood of all five species (n=92 individuals) using the standard phenol:chloroform extraction method. Mitochondrial and nuclear markers were analyzed using Likelihood and Bayesian methods to establish phylogenetic relationships and to determine speciation patterns. MtDNA barcoding using the cytochrome c oxidase subunit 1 (CO1) gene was used to assign individuals to species. The construction of a neighbour-joining and a maximum likelihood tree provided graphic representations of the pattern of divergences between the five Cossypha species. Individuals from a species clustered together with strong bootstrap values. These procedures were accomplished using MEGA software. PopART was used to construct a minimum spanning network. This network illustrated similarity between the five species with regards to the CO1 barcode. Only seven of thirteen novel microsatellite markers were able to cross amplify in all five species. The Bayesian clustering analysis using the statistical programme STRUCTURE identified three genetic clusters (K=3) with the three distinct species being C. dichroa, C. natalensis, and C. caffra. Cossypha heuglini cluster amongst C. dichroa, C. natalensis, and C. caffra, while C. humeralis clusters amongst C. natalensis. Despite the hybridization events recorded between C. dichroa and C. natalensis these two species do not appear to be each other’s closest relatives according to microsatellite and mtDNA analysis. The hybridization events indicate their ability to overcome reproductive isolation mechanisms such as vocalisations. === MT 2017
author Munshi, Naadhirah
author_facet Munshi, Naadhirah
author_sort Munshi, Naadhirah
title Genetic diversity and interspecies hybridization in Cossypha robin-chats
title_short Genetic diversity and interspecies hybridization in Cossypha robin-chats
title_full Genetic diversity and interspecies hybridization in Cossypha robin-chats
title_fullStr Genetic diversity and interspecies hybridization in Cossypha robin-chats
title_full_unstemmed Genetic diversity and interspecies hybridization in Cossypha robin-chats
title_sort genetic diversity and interspecies hybridization in cossypha robin-chats
publishDate 2017
url Munshi, Naadhirah (2017) Genetic diversity and interspecies hybridization in cossypha robin-chats, University of the Witwatersrand, Johannesburg, <http://hdl.handle.net/10539/23464>
http://hdl.handle.net/10539/23464
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