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Gewählte Diplomarbeit / Masterarbeit:

John Mwaura Kariuki (2018): Microsatellite Cross-Species Amplification and Utility in Selected African Cichlids: A Valuable Tool for Tilapiine Fishery Management and Conservation.
Diplomarbeit / Masterarbeit - Institut für Integrative Naturschutzforschung, BOKU-Universität für Bodenkultur, pp Total 78. UB BOKU obvsg FullText

Datenquelle: ZID Abstracts
Abstract:
Oreochromis niloticus is one of the most farmed fish in the world, coming only second to carp. This has led to its massive relocation far from its native range mainly for aquaculture purposes. As a result, it has hybridized with other tilapiine species thus running the risk of losing pure breeds through introgression. This study aimed at developing microsatellite markers from Oreochromis niloticus, designing primers for these markers and then testing their ability to cross-amplify DNA from 2 other tilapiine species i.e. Sarotherodon galilaeus, Tilapia zillii during a PCR reaction. The study also aimed at using the developed microsatellite markers to determine genetic structure of these tilapiine species. Consequently, it was possible to postulate the level of hybridization within these species. Forty-two microsatellite markers were developed consisting of the following repeats: 8 dinucleotides, 9 trinucleotides, 16 tetra nucleotides and 9 penta nucleotides. After running PCR reaction using the designed primers, amplicons were sequenced on a high throughput illumina MiSeq sequencing platform. Two methods were used in genotyping the sequence data and the results compared in terms of genetic structure and allelic numbers they produced. Whole sequence information (WSI) method, also called haplotype, gave the highest values in mean alleles per locus and polymorphic information content at 14.86 and 0.58, while sequence length genotyping method gave the least at 2.02 and 0.22 respectively. Thirty-two out of the 42 of the microsatellite primer pairs designed cross-amplified in S. galilaeus and 23 in Coptodon zillii. Possible hybridization and hence gene flow was observed especially in the two Nile tilapia populations from Lake Victoria and Lake Albert. Microsatellite markers developed in this study showed high level of cross-amplification and polymorphism and thus usable in monitoring hybridization in tilapiine species.

Beurteilende(r): Meimberg Harald
1.Mitwirkender: Cardoso Curto Manuel Antonio

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