Masters Degrees (Genetics)

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Browsing Masters Degrees (Genetics) by Author "Ghosh, S."

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    Description of novel species of psychedelic mushrooms from Southern Africa
    (University of the Free State, 2022) Maloka, Onalerona Orefilempho; Gryzenhout, M.; Ghosh, S.
    The chemical compound psilocybin, responsible for causing hallucinations, is found in mushroom species of genera such as Gymnopilus, Panaeolus, Pluteus, and Psilocybe. Psilocybin also has a number of psychiatric and medical applications. Psilocybin-producing mushrooms have a wide distribution in South Africa and other parts of the world, but the biodiversity of these fungi is poorly known in South Africa. This study focused on the species identification of two sets of collections of Psilocybe, one from Lesotho and the other from Pretoria, based on morphology and different DNA sequence phylogenetic markers. A multi-locus phylogeny was constructed using the Internal Transcribed Spacer (ITS), RNA Polymerase II (RPB 1), and Translational Elongation Factor 1α (TEF-1α) gene regions. More than one marker was used to confirm identifications, and by combining the sequences, to also obtain better statistical support for groupings. By using the additional genes besides ITS, the usefulness of these additional markers to identify Psilocybe species was also investigated. Results showed that the two collections of samples were unique and different from each other based on all of the genes, except for the RPB 1 region that was found wanting. Although the TEF-1α was found sufficiently variable to also distinguish species similar to the ITS region, a relatively small number of species have been sequenced up to date. The distinct grouping of the two collections was confirmed by a number of macro- and micromorphological characteristics, and described as Psilocybe malotiensis prov. nom. and Psilocybe orontawuli prov. nom. respectively. Results from this study represent an important breakthrough where Southern African samples can now be sequenced and compared with specimens from elsewhere and should illustrate the presence of numerous novel species occurring in this region.
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    Skin microbiome diversity of batrachochytrium dendrobatidis-challenged phofung river frogs (amietia hymenopus) in the Drakensberg mountain range
    (University of the Free State, 2022) Kloppers, George Antonie Ehlers; Gryzenhout, M.; Gryzenhout, C.; Cason, E.; Ghosh, S.
    Infectious diseases are pressuring amphibian populations globally, especially threatened frog species occurring in restricted areas. Chytridiomycosis, which is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is arguably the most devastating panzootic disease confronting wildlife today and was determined to be a major driving force of the current amphibian extinction crisis. A healthy amphibian host has a symbiotic relationship with its cutaneous microbial community that benefits the host in many ways including the protection against malicious microbes. The current trend in amphibian skin microbiome studies concentrate predominantly on its bacterial component, while other components of the microbiome such as filamentous fungi and eukaryotes have been neglected. In this study Amietia hymenopus, a Bd-challenged frog population of southern Africa, was sampled from remote locations of the frog?s natural distribution on the Drakensberg mountain range. The cutaneous microbiome diversity was analysed using next generation sequencing and bioinformatics tools, investigating both the bacterial and fungal components of the frogs? skin microbial community. Results indicated high diversity dissimilarities in both alpha and beta diversity when comparing individual specimens, and sampling areas, respectively. This study touched on an important topic regarding the microbial biodiversity found on frogs, and sheds light on the complex interaction between host and microbial communities in amphibian populations. Knowledge on this intricate relationship between host and their microscopic cutaneous symbionts could help inform amphibian conservation efforts against infectious disease.