Project description:The emergence and fast global spread of COVID-19 has presented one of the greatest public health challenges in modern times with no proven cure or vaccine. Africa is still early in this epidemic, therefore the extent of disease severity is not yet clear. We used a mathematical model to fit to the observed cases of COVID-19 in South Africa to estimate the basic reproductive number and critical vaccination coverage to control the disease for different hypothetical vaccine efficacy scenarios. We also estimated the percentage reduction in effective contacts due to the social distancing measures implemented. Early model estimates show that COVID-19 outbreak in South Africa had a basic reproductive number of 2.95 (95% credible interval [CrI] 2.83–3.33). A vaccine with 70% efficacy had the capacity to contain COVID-19 outbreak but at very higher vaccination coverage 94.44% (95% Crl 92.44–99.92%) with a vaccine of 100% efficacy requiring 66.10% (95% Crl 64.72–69.95%) coverage. Social distancing measures put in place have so far reduced the number of social contacts by 80.31% (95% Crl 79.76–80.85%). These findings suggest that a highly efficacious vaccine would have been required to contain COVID-19 in South Africa. Therefore, the current social distancing measures to reduce contacts will remain key in controlling the infection in the absence of vaccines and other therapeutics.
Project description:We use ZooMS to obtain secure species identifications of key specimens of early domesticated fauna from South Africa, dating to ca. 2000 BP. Because it can be difficult to distinguish between fragmentary remains of early domesticates (sheep) and similar-sized local wild bovids (grey duiker, grey rhebok, springbok) based on morphology alone, we explore the use of biomolecular methods to make these distinctions. As well as the traditional method of analysing bone fragments, we show the utility of minimally destructive sampling methods such as PVC eraser and polishing films for successful ZooMS identification. We also show that collagen extracted more than 25 years ago for the purpose of radiocarbon dating can yield successful ZooMS identification. Our study demonstrates the importance of developing appropriate regional frameworks of comparison for future research using ZooMS as a method of biomolecular species identification on archaeological faunal assemblages. We confirm that the specimen from the site of Spoegrivier dated to 2105±65 BP is indeed a sheep. This is the earliest directly dated evidence of domesticated animals in southern Africa.
Project description:Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with one of the highest world incidences in the Eastern Cape region of South Africa. Several genome wide studies have been performed on ESCC cohorts from Asian countries, North America, Malawi and other parts of the world but none has been conducted on ESCC tumors from South Africa to date, where the molecular pathology and etiology of this disease remains unclear. We report here tumor associated copy number changes observed in 51 ESCC patients’ samples from the Eastern Cape province of South Africa. We extracted tumor DNA from 51 archived ESCC specimens and interrogated tumor associated DNA copy number changes using Affymetrix® 500K SNP array technology. The Genomic Identification of Significant Targets in Cancer (GISTIC) algorithm was applied to identify significant focal regions of gains and losses. Gains of the top recurrent cancer genes were validated by fluorescence in situ hybridization and their protein expression assessed by immunohistochemistry. Twenty-three significant focal gains were identified across samples. Gains involving the CCND1, MYC, EGFR and JAG1 loci recapitulated those described in studies on Asian and Malawian cohorts. The two most significant gains involved the chromosomal sub-bands 3q28, encompassing the TPRG1 gene and 11q13.3 including the CTTN, PPFIA1and SHANK2 genes. There was no significant homozygous loss and the most recurrent hemizygous deletion involved the B3GAT1 gene on chromosome11q25. Focal gains on 11q13.3 in 37% of cases (19/51), consistently involved CTTN and SHANK2 genes. Twelve of these cases (23,5%), had a broader region of gain that also included the CCND1, FGF19, FGF4 and FGF3 genes. SHANK2 and CTTN are co-amplified in several cancers, these proteins interact functionally together and are involved in cell motility. Immunohistochemistry confirmed both Shank2 (79%) and cortactin (69%) protein overexpression in samples with gains of these genes. In contrast, cyclin D1 (65%) was moderately expressed in samples with CCND1 DNA gain. This study reports copy number changes in a South African ESCC cohort and highlights similarities and differences with cohorts from Asia and Malawi. Our results strongly suggest a role for CTTN and SHANK2 in the pathogenesis of ESCC in South Africa.
2020-04-07 | GSE59105 | GEO
Project description:Survey of RNA viruses infecting termite species
Project description:Genetic analysis of interspecific populations derived from crosses between the wild tomato species Solanum habrochaites f glabratum, which synthesizes and accumulates insecticidal methylketones (MKs) such as 2-undecanone and 2-tridecanone in glandular trichomes, and Solanum lycopersicum (cultivated tomato), which does not, demonstrated that MK metabolism in the wild species can be attributed to several loci. Comparative trascriptome analysis of the glandular trichomes of F2 segregants bulked into low- and high-MK plants identified several genes whose transcripts were either more or less abundant in the high-MK plants.
Project description:In this study two Viperidae species, living in two different habitats, the horned desert viper (Cerastes cerastes) native to the deserts in North Africa and in turn the mangrove pit viper (Cryptelytrops purpureomaculatus), which can be found in South/Southeast Asia, were studied in terms of the identification of the venom proteome.
Project description:RNA-seq of seedlings of four tomato species Solanum habrochaites, Solanum lycopersicum, Solanum pimpinelliolium, and Solanum pennellii. An additional panel of samples include many tissues from Solanum lycopersicum and Solanum pennellii in two light conditions
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:Age-matched K18-hACE2 transgenic mice were infected intranasally with different SARS-CoV-2 viruses, including (1) USA-WA1/2020 (WA) of lineage A, (2) New York-PV09158/2020 (NY) of lineage B.1.3, (3) USA/CA_CDC_5574/2020 (CA) of lineage B.1.1.7 and (4) hCoV-19/South Africa/KRISP-EC-K005321/2020 (SA) of lineage B.1.351. Mouse lungs were harvested on 3 days post infection (dpi). Total RNA was extracted using QIAgen RNeasy Plus Mini Kit and was reverse transcribed using the High-Capacity cDNA Reverse Transcription Kit (Thermo Fisher Scientific). Resultant cDNA was used as the template along with RT2 SYBR Green ROX qPCR Mastermix (Qiagen) to perform RT² Profiler™ PCR Array Mouse Hypoxia Signaling Pathway (Qiagen) real-time PCR in Stratagene MX3000p qPCR system.