Project description:Three new Fusarium species, F. convolutans, F. fredkrugeri, and F. transvaalense (Ascomycota, Hypocreales, Nectriaceae) are described from soils collected in a catena landscape on a research supersite in the Kruger National Park, South Africa. The new taxa, isolated from the rhizosphere of three African herbaceous plants, Kyphocarpa angustifolia, Melhania acuminata, and Sida cordifolia, are described and illustrated by means of morphological and multilocus molecular analyses based on sequences from five DNA loci (CAL, EF-1 α, RPB1, RPB2 and TUB). According to phylogenetic inference based on Maximum-likelihood and Bayesian approaches, the newly discovered species are distributed in the Fusarium buharicum, F. fujikuroi, and F. sambucinum species complexes.
Project description:Two new species of the families Polyxenidae and Synxenidae, are described from Table Mountain National Park, South Africa. Propolyxenus squamatussp. n. (Polyxenidae) has tergites I-X mostly covered by scale-shaped trichomes directed caudally, a character previously known only in Synxenidae. The structure of scale-shaped dorsal trichomes is different to that of the scales in Phryssonotus and Condexenus species. Phryssonotus brevicapensissp. n. (Synxenidae) is the only known species of the genus Phryssonotus having 11 tergites, (including collum and telson) and 15 pairs of legs, as in Condexenus biramipalpus Nguyen Duy-Jacquemin, 2006. These two species therefore appear to occupy an intermediate position between Phryssonotus (12 tergites) and Polyxenoidea (maximum of 11 tergites).
Project description:Morphology, phylogeny, and sexual stage of Fusarium caatingaense and Fusarium pernambucanum, new species of the Fusarium incarnatum-equiseti species complex associated with insects in Brazil
Project description:Chronic herbivory by elephants rarely eliminates any species of woody savanna plants because these plants are typically vigorous basal resprouters after damage by fire or herbivory. In some instances, resprouting after elephant herbivory even increases stem numbers per unit area compared to protected areas. It is thus difficult to know whether an area has been severely degraded by elephant herbivory or not because although trees may be severely reduced in size, they will still be present and may even be relatively dense. By using an elephant exclosure in the Kruger National Park, South Africa, we demonstrate that this resprouting ability masks the fact that entire populations of a widespread African palm, Hyphaene petersiana, are prevented from reaching sexual maturity by chronic elephant herbivory. Besides sterilizing these palms and thus preventing their evolution and seed dispersal, the absence of the palm fruits, flowers and tall stems has other negative biodiversity impacts on their associated fauna. We suggest that to determine sustainable elephant impacts on savanna plants, conservation managers also use the reproductive condition of savanna plants rather than their presence, height or stem density.
Project description:Fusarium spp. are fungal pathogens of humans and plants. Fusarium oxysporum and Fusarium solani are important species isolated from infections such as onychomycosis, fungal keratitis, invasive infections, and disseminated diseases. These pathologies have a very difficult therapeutic management and poor therapeutic responses, especially in patients with disseminated infection. Little information is available regarding the molecular mechanisms responsible for antifungal resistance in these fungi. methods: In this study, we performed a quantitative analysis of the transcriptional profile of F. oxysporum and F. solani, challenged with amphotericin B (AMB) and posaconazole (PSC) using RNA-seq. Quantitative real-time reverse transcription PCR (qRT-PCR) was used to validate the results results: Several genes related to mechanisms of antifungal resistance such as efflux pumps, ergosterol pathway synthesis, and responses to oxidative stress were found. Genes such as ERG11, ERG5, the Major Facilitator Superfamily (MFS), thioredoxin, and different dehydrogenase genes may explain the reduced susceptibility of Fusarium spp. against azoles and the possible mechanisms that may play an important role in induced resistance against polyenes. conclusions: Important differences in the levels of transcriptional expression were found between F. oxysporum and F. solani exposed to the two different antifungal treatments. Knowledge on the gene expression profiles and gene regulatory networks in Fusarium spp. during exposure to antifungal compounds, may help to identify possible molecular targets for the development of novel, better, and more specific therapeutic compounds. profile transcriptional of Fusarium spp changed to antifungal treatments in vitro
Project description:Fusarium spp. are fungal pathogens of humans and plants. Fusarium oxysporum and Fusarium solani are important species isolated from infections such as onychomycosis, fungal keratitis, invasive infections, and disseminated diseases. These pathologies have a very difficult therapeutic management and poor therapeutic responses, especially in patients with disseminated infection. Little information is available regarding the molecular mechanisms responsible for antifungal resistance in these fungi. methods: In this study, we performed a quantitative analysis of the transcriptional profile of F. oxysporum and F. solani, challenged with amphotericin B (AMB) and posaconazole (PSC) using RNA-seq. Quantitative real-time reverse transcription PCR (qRT-PCR) was used to validate the results results: Several genes related to mechanisms of antifungal resistance such as efflux pumps, ergosterol pathway synthesis, and responses to oxidative stress were found. Genes such as ERG11, ERG5, the Major Facilitator Superfamily (MFS), thioredoxin, and different dehydrogenase genes may explain the reduced susceptibility of Fusarium spp. against azoles and the possible mechanisms that may play an important role in induced resistance against polyenes. conclusions: Important differences in the levels of transcriptional expression were found between F. oxysporum and F. solani exposed to the two different antifungal treatments. Knowledge on the gene expression profiles and gene regulatory networks in Fusarium spp. during exposure to antifungal compounds, may help to identify possible molecular targets for the development of novel, better, and more specific therapeutic compounds.
Project description:The Afrikaner population of South Africa are the descendants of European colonists who started to colonize the Cape of Good Hope in the 1600s. In the early days of the colony, mixed unions between European males and non-European females gave rise to admixed children who later became incorporated into either the Afrikaner or the “Coloured" populations of South Africa. Differences in ancestry, social class, culture, sex ratio and geographic structure led to distinct characteristic admixture patterns in the Afrikaner and Coloured populations. The Afrikaner population has a predominant European composition, whereas the Coloured population has more diverse ancestries. Genealogical records previously estimated the contribution of non-Europeans into the Afrikaners to be between 5.5%-7.2%. NB two individuals withdrew consent so this data contains only 75 individuals as compared to the 77 cited in the article.
Project description:A new species of freshwater crab, Potamonautesisimangaliso sp. n., is described from the western shores of False Bay, Hluhluwe, within the iSimangaliso Wetland Park, South Africa. While bearing a superficial resemblance to Potamonauteslividus, the new species has been found to be genetically distinct, diverging from the former by 7.4-7.8% in mtDNA. Potamonautesisimangaliso most closely resembles Potamonauteslividus, but is distinguished by a unique suite of carapace characters, colouration, and size. The new species also lives in close association with oxygen-poor, fresh ephemeral pans, while the habitat of Potamonauteslividus is well above the surface water line of the closest water body. An updated identification key for the Potamonautes species of South Africa is provided.