A5044059521- Plant Virus Research Studies
- Marine Sponges and Natural Products
- Microbial Natural Products and Biosynthesis
- Genomics and Phylogenetic Studies
- Viral Infectious Diseases and Gene Expression in Insects
- Microbial Community Ecology and Physiology
- Enzyme Structure and Function
- Marine Biology and Ecology Research
- Bacteriophages and microbial interactions
- Amino Acid Enzymes and Metabolism
- Enzyme Catalysis and Immobilization
- Coastal and Marine Management
- Bacterial Genetics and Biotechnology
- Aquaculture disease management and microbiota
- Polyamine Metabolism and Applications
- Microbial Metabolic Engineering and Bioproduction
- Fungal and yeast genetics research
- Polar Research and Ecology
- Insect Resistance and Genetics
- Paleontology and Stratigraphy of Fossils
- RNA and protein synthesis mechanisms
- Isotope Analysis in Ecology
- Coral and Marine Ecosystems Studies
- Marine and coastal ecosystems
- Heat shock proteins research
Rhodes University
2015-2025
South African Institute for Aquatic Biodiversity
2018-2024
Nelson Mandela University
2019
University of Cape Town
1989-2005
University of Tennessee Health Science Center
1993-2002
The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage lobe-finned fish thought to have become extinct 70 million years ago. modern looks remarkably similar many its ancient relatives, and evolutionary proximity our own ancestors provides glimpse the that first walked on land. Here we report genome sequence African coelacanth, Latimeria chalumnae. Through phylogenomic analysis, conclude lungfish, not is closest relative tetrapods. Coelacanth protein-coding...
Following the first description of living marine stromatolites along South African east coast, new investigations south coast have revealed occurrence extensive fields actively calcifying stromatolites. These been recorded at regular distances a 200-km stretch coastline, from Cape Recife in to Storms River mouth west, with highest density found between Schoenmakerskop and Maitland mouth. All active are associated freshwater seepage streams flowing dune cordon, which form rimstone dams other...
Abstract The Southern Ocean accounts for ∼30% of the ocean's CO 2 sink, partly due to its biological pump that transfers surface‐produced organic carbon deeper waters. To estimate large‐scale export potential and characterize drivers, we measured nitrogen isotope ratios surface suspended particulate matter (δ 13 C SPM , δ 15 N ) samples collected in summer 2016/2017 during Antarctic Circumnavigation Expedition (364 stations). Concurrent measurements phytoplankton community composition...
The Latrunculiidae are a family of cold water sponges known for their production bioactive pyrroloiminoquinone alkaloids. Previously it was shown that the bacterial community associated with Tsitsikamma sponge species comprises unusual taxa and is dominated by novel Betaproteobacterium. Here, we have characterized communities six latrunculid representing three genera (Tsitsikamma, Cyclacanthia, Latrunculia) as well Mycale species, collected from Algoa Bay on South African southeast coast....
In 2016, South Africa became the first African country to draft Marine Spatial Planning (MSP) legislation. The underlying legal framework supports achievement of ecological, social and economic objectives, but a national policy grow oceans economy provides challenge for ecosystem-based approaches MSP. During 2018 International Conservation Congress in Borneo, we convened special session discuss particular challenges that will likely apply any developing seeking increase profits from...
An investigation of living phosphatic stromatolites from Schoenmakerskop barrage pool near Gqeberha (Port Elizabeth), South Africa, yielded new cyclic octadepsipeptides, amatyemides A (1) and B (2), named using the Xhosa word 'amatye' for 'rock'. The were isolated methanol extracts a targeted stromatolite sample collection, following an initial metabolomic survey pool. Planar structure elucidation 1 2 relied on NMR LCMS2 data, which delineated same six amino acids one...
Expression of the nitrogen catabolic genes in Saccharomyces cerevisiae, including those gamma-aminobutyric acid (UGA) and allantoin (DAL) pathways, is regulated positively by GLN3 protein negatively DAL80 protein. The deduced sequences proteins contain a zinc finger motif homologous to shown bind GATA sequences. In addition, has been directly pair GATA-containing (URSGATA) vitro, (UASNTR) required for GLN3-dependent transcriptional activation heterologous expression vector. We demonstrate...
Southern Africa occupies a critical position within the southern hemisphere for study of broadscale global change and three oceans around South (the Atlantic, Indian Oceans) play vital role in determining local regional climate weather patterns.Oceans coasts also provide various resources services (e.g.food carbon sequestration), but these are threatened by human activities.Uncertainty impact consequences anthropogenic activities makes it problematic to manage marine resources.Given recent...
The temperate marine sponge, Tsitsikamma favus, produces pyrroloiminoquinone alkaloids with potential as anticancer drug leads. We profiled the secondary metabolite reservoir of T. favus sponges using HR-ESI-LC-MS/MS-based molecular networking analysis followed by preparative purification efforts to map diversity new and known pyrroloiminoquinones related compounds in extracts seven specimens. Molecular taxonomic identification confirmed all five specimens (chemotype I) were found produce...
Lithified layers of complex microbial mats known as microbialites are ubiquitous in the fossil record, and modern forms increasingly identified globally. A key challenge to developing an understanding microbialite formation environmental role is how investigate diverse communities situ . We selected living, layered (stromatolites) a peritidal environment near Schoenmakerskop, Eastern Cape, South Africa conduct spatial survey mapping composition small molecule production from samples....
The nucleotide sequence of a 3,202-base-pair fragment which contained the minimum region required for replication broad-host-range plasmid, pTF-FC2, has been determined. At least five open reading frames and that affected host range were identified. Proteins corresponding in size location to four produced an vitro transcription-translation system. predicted amino acid sequences two proteins aligned with those RepA RepC IncQ plasmid RSF1010 found be 43 60% homologous, respectively. Despite...
The Department of Science and Technology's (DST's) 10-year Global Change Grand Challenge programme requires platforms to 'attract young researchers the region retain them by exciting their interest in aspects global change; while developing capacity professional skills relevant fields investigation' 1 .In addition, July 2014, President Zuma officially launched Operation Phakisa announced that a key target this Oceans Economy initiative would be 'for Higher Education Training drive alignment...
Emerging viral diseases, most of which are zoonotic, pose a significant threat to global health. There is critical need identify potential new pathogens and the challenge reservoirs from these viruses might emerge. Deep sequencing invertebrate transcriptomes has revealed plethora viruses, many represent novel lineages representing both plant animal little known about that pose.Providence virus, an insect was used establish productive infection in Vigna unguiculata (cowpea) plants. Providence...
South Africa has a long track record in Southern Ocean and Antarctic research recently invested considerable funds acquiring new infrastructure for ongoing support of this research. This includes base at Marion Island purpose-built ice capable vessel, which greatly expand opportunities. Despite investment, Africa’s standing as participant critical field is threatened by confusion, lack funding, consultation transparency. The endeavour presently bedevilled political manoeuvring among groups...
Stromatolites are complex microbial mats that form lithified layers. Fossilized stromatolites the oldest evidence of cellular life on Earth, dating back over 3.4 billion years. Modern relatively rare but may provide clues about function and evolution their ancient counterparts. In this study, we focus peritidal occurring at Cape Recife Schoenmakerskop southeastern South African coastline, former being morphologically structurally similar to fossilized phosphatic formations. Using assembled...
Expression of the DAL2, DAL4, DAL7, DUR1.2 , and DUR3 genes n S.cerevisiae is induced by allophanate, last intermediate in allantoin catabolic pathway. Analysis DAL7 promoter identified a dodecanucleotide, UIS which was required for inducer-responsiveness. Operation functional DAL81 DAL82 gene products. Since product not an pathwayspecific regulatory factor, considered as more likely candidate to be DAL binding protein. Using E.coli expression system, we showed that protein specifically...
The minimum region required for replication of the broad-host-range Thiobacillus ferrooxidans plasmid pTF-FC2 in Escherichia coli was shown to be contained on a 2.05-kilobase fragment DNA. A 184-base-pair that cis identified. This also involved incompatibility. Nucleotide sequencing this revealed three perfectly conserved 22-base-pair tandemly repeated sequences. comparison with equivalent R1162 showed sequences had 60% nucleotide homology. 106-base-pair immediately adjacent 75% homologous....
The Tetraviridae are a family of small, non-enveloped, insect RNA viruses consisting one or two single-stranded, positive-sense genomic RNAs encapsidated in an icosahedral capsid with T=4 symmetry. Tetravirus procapsids undergo maturation when exposed to low pH environment vitro. While the structural biology conformational changes that mediate acid-dependent is well understood, little known about significance vivo. To address this question, capsid-coding sequence tetravirus Helicoverpa...
Providence virus (PrV) is a member of the family Tetraviridae, small, positive-sense, ssRNA viruses that exclusively infect lepidopteran insects. PrV only known tetravirus replicates in tissue culture. We have analysed genome and characterized viral translation products, showing has monopartite encoding three ORFs: (i) p130, unique to unknown function; (ii) p104, which contains read-through stop signal, producing an N-terminal product 40 kDa (p40) (iii) capsid protein precursor (p81). There...