Browsing Research articles (Dept of Biological Sciences) by Author "Mpoloka, S.W."
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Mpoloka, S.W.; Kgotlele, T.; Wally, A. (Academic Journals, www.academicjournals.org, April 17, 2008)[more][less]
Abstract: Allele frequencies for nine short tandem repeat (STR) loci from the AmpFlSTR® Profiler Plus PCR Amplification Kit were determined in five subpopulations across Botswana and tested for suitability for use in individual identification. DNA was extracted from whole blood samples collected from 150 unrelated individuals. Targeted regions of DNA (vWA, FGA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D18S51, D21S11 and the sex determining locus Amelogenin) were amplified using multiplexed PCR. The alleles showed a high degree of polymorphism, with heterozygosity above 67%, indicating that there is no significant inbreeding within the subpopulations. Matching probability was below 0.2 hence power of discrimination was high, indicating that the alleles from the five subpopulations can be used in human identifications. The present study is the first reported attempt at determining allele frequencies of subpopulations in Botswana and could possibly be used in developing a national DNA database. URI: http://hdl.handle.net/10311/1010 Files in this item: 1
mpoloka ajb paper.pdf (292.5Kb) -
Mpoloka, S.W. (Academic Journals. http://www.academicjournals.org/AJB, NaN, 2008)[more][less]
Abstract: Over the past few decades, there has been a depletion of the stratospheric ozone layer due to emissions of halogen-containing compounds of anthropogenic origin. This has resulted in a concomitant increase in solar ultraviolet-B radiation. High levels of UV-B radiation are responsible for multiple biologically harmful effects in both plants and animals. In plants, these effects include DNA damage, which often causes heritable mutations affecting various physiological processes, including the photosynthetic apparatus, protein destruction and signal transduction via UV-B photoreceptors. High UV-B levels introduce a number of different lesions, predominantly cyclobutane pyrimidine dimmers (CPDs) and pyrimidine (6-4) pyrimidinone products [(6-4) PPs] in the genome. These could adversely affect plant growth, development and morphology, especially the productivity of sensitive crop species. This paper reviews the genetic effects of long-term UV-B exposure in plants. URI: http://hdl.handle.net/10311/491 Files in this item: 1
Effects of prolonged.pdf (2.345Mb) -
Mpoloka, S.W. (American-Eurasian Network for Scientific Information. http://www.aensi.org/aeb_online.html, NaN, 2008)[more][less]
Abstract: The nuclear 18S rDNA and chloroplast encoded rbcL gene sequences were used to investigate the evidence of residual UV-B induced mutagenesis in Dimorphotheca sinuata plants. The probes were generated by the polymerase chain reaction and labelled with a non-radioactive Digoxigenin label and used in Southern hybridization studies. High levels of variability in the 18S rDNA gene were found, pointing to genome rearrangements and possibly genome instability due to UV-B effects. URI: http://hdl.handle.net/10311/484 Files in this item: 1
Investigating evidence.pdf (1.233Mb) -
Mpoloka, S.W. (Academic Journals, www.academicjournals.org, August 18, 2010)[more][less]
Abstract: Residual long-term effects of increased UV-B radiation were investigated in an indigenous plant species, Dimorphotheca sinuata, by analysing photosynthetic gene expression. Reductions were observed in the amount of the rbcL and psbA mRNA expressed in progeny of plants that were previously subjected to enhanced UV-B levels. However, observed reductions did not attain statistical significance. This could explain the reduction in net biomass and physiological and biochemical parameters observed by other researchers as a result of UV-B exposure. Results from this study with plants grown in the absence of UV-B point to changes in the regulation of photosynthetic genes and such mutations due to raised UV-B levels could cause permanent changes in plant populations. URI: http://hdl.handle.net/10311/1011 Files in this item: 1
Mpoloka SRE 2010.pdf (122.9Kb)
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