published_or_final_version / abstract / Statistics and Actuarial Science / Doctoral / Doctor of Philosophy

<p>The aim of this study was to investigate the forensic usefulness of various Y-chromosome short tandem repeat loci among South African sub-populations. Three different sets of Y-chromosome short tandem repeat loci were chosen for investigation.</p>

Messenger ribonucleic acid (mRNA) turns out to be an increasingly important molecule in forensic analysis of biological samples. Because of the specific role of mRNA in all living cells to transfer genetic information from DNA to proteins, mRNA is able to provide cell-specific information and regulate control of gene expression. mRNA analysis performed on an extracted mRNA sample isolated from a biological stain of a crime scene can be used to identify the nature of the tissue(s) comprising the stain. In this research, the effects of a couple of mRNA storage conditions such as cold temperature and ultraviolet light exposure on mRNA integrity from human saliva have been evaluated. Human saliva samples have been sampled and exposed to UV light and freezing temperature (-20°C) for varying lengths of time. Extracted mRNA from each sample has been quantified spectrophotometrically and subjected to real time RT-PCR to evaluate stability and integrity of one of the saliva marker transcripts, KRT13 mRNA, of treated samples compared to untreated samples. The results of this study indicated that UV light and freezing temperature don’t have a significant effect on the integrity of KRT13 mRNA. There is also no apparent correlation between Ct values of treated samples and treating intervals. This research holds important implications for the use of mRNA for applications in forensic science, an area which has not been researched extensively. / Department of Biology

<p>The aim of this study was to investigate the forensic usefulness of various Y-chromosome short tandem repeat loci among South African sub-populations. Three different sets of Y-chromosome short tandem repeat loci were chosen for investigation.</p>

Thesis (Ph. D.)--Ohio University, August, 2004. / Includes bibliographical references (p. 185-196).

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vi, 60 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 58-60).

Thesis (Ph.D.)--Ohio University, August, 2004. / Title from PDF t.p. Includes bibliographical references (p. 185-196)

Thesis (MDip (Medical Technology))--Cape Technikon, 1993 / The use of genetic marker testing to resolve cases of disputed paternity, is well established. The number and range of systems used depends on the expertise of the laboratory, and for this reason various laboratories offer different systems. Standard testing includes tests in the following genetic marker systems: human leukocyte antigen (tissue) typing; red cell blood groups; and red cell enzyme and serum protein testing. The Provincial Laboratory for Tissue Immunology currently offers a range of 16 genetic marker systems capable of excluding >99% of falsely accused men. Following the discovery DNA polymorphisms, particularly VNTR DNA polymorphisms, and the commercial availability of VNTR DNA probes, PLTI decided to offer this service to our clients. This study was the initial phase in the establishment of a VNTR DNA typing laboratory and covered the determination of inter-and intra-gel accuracy and precision, selection of restriction enzyme/probe combination, and evaluation and comparison of the results of 100 disputed paternity cases tested using both standard and VNTR DNA typing. Of the 100 cases tested, in 33 cases, the putative father was excluded using standard testing. These exclusions were confirmed using VNTR DNA typing, and, furthermore, an additional two exclusions of paternity were shown using only VNTR DNA typing. In another two cases of disputed paternity, the exclusions obtained using standard tests required further confirmation. VNTR DNA typing convincingly excluded both falsely accused putative fathers. The VNTR DNA typing laboratory now functions as an integral part of the disputed paternity service. Due to the cost and time involved in VNTR DNA typing it is reserved at this stage for: those cases which require further confirmation of the results of standard testing; when the probability of paternity is low (<99.7%); or when a specific request is made.

Magister Scientiae - MSc / The aim of this study was to investigate the forensic usefulness of various Y-chromosome short tandem repeat loci among South African sub-populations. Three different sets of Y-chromosome short tandem repeat loci were chosen for investigation. / South Africa

A dissertation submitted in fulfilment of the requirements for the degree of Master of Science to the Faculty of Science, University of the Witwatersrand, Johannesburg, 2017 / Transcription factors are proteins that are involved in the regulation of gene expression and are responsible for the tight control of transcription allowing a cell to react to changes in its environment. Transcription factors are thus highly regulated by a variety of mechanisms which include phosphorylation. Forkhead box P2 (FOXP2) is a transcription factor expressed in multiple tissues during embryonic development. FOXP2 like other FOX proteins contains a DNA binding domain known as the forkhead domain (FHD). The effect of phosphorylation of serine 557 in the FHD on the structure and DNA binding was done using a glutamate mutant (to mimic phosphorylation) and an alanine mutant (as a control). Structural characterisation was performed using size exclusion chromatography (SEC), intrinsic fluorescence and far-UV circular dichroism. The effect of phosphorylation on DNA binding was observed using electrophoretic mobility shift assay (EMSA) and isothermal titration calorimetry (ITC). Far-UV circular dichroism and intrinsic fluorescence of the mutants and wild type did not reveal any significant secondary or tertiary structural changes. SEC however revealed a decrease in dimerisation propensity in the Ser557 mutants when compared the wild type (WT). EMSA revealed that DNA binding of S557E is only observed at protein concentrations 40 times in excess of the DNA. DNA binding of the WT and S557A mutants is observed at 5 times and 20 times excess protein respectively. However, using ITC no DNA binding is observed for either S557E or S557A FOXP2 FHD. Thus, it is possible that phosphorylation of serine 557 in the FOXP2 FHD could be a mechanism for inactivation of FOXP2. / XL2017