Allozyme variation within and differentiation between populations and genera of representatives of the tigerfish family

Ph.D.Since the systematics in the family Characidae from southern Africa were only reliant on some morphological traits, the determination of the genetic variation, genetic distances and phylogenetic relationships using different molecular techniques led to the formulation of this study. The first aim of the study was to describe the amount and pattern of genetic variation withi~ and between populations. The analysis of the isozymes provided the first account of the amount. pattern and distribution of genetic variation within this family. A general introduction on the history, distribution, descriptions, taxonomy and some ecological notes from the literature on southern African Characidae species is included in Chapter l. The second chapter dealt with the Hydrocynus genus that represents, morphologically, the largest member of this family. Other members of the Characidae family are relatively small species that do not exceed 300g. Twenty-five enzyme coding loci in two populations of H. vittatus, from Namibia and South Africa, were analyzed by horizontal starch gelelectrophoresis. Electrophoretic analysis of liver. white muscle, heart and testis samples revealed genetic variation at 20% (Upper Zambezi River. Namibia) and 36% (Oiifants River. South Africa) of the protein coding loci studied. Average heterozygosity values ranged from l .9% (Upper Zambezi River) to 4.6% (Oiifants River), with a genetic distance value of 0.005 between these populations. The low amount of genetic variability in the former population compared to that of other fish species from the same geographical area, and to that of H. vittatus from the Olifants River. can be attributed to restricted gene flow due to isolation. Although morphological differences exist between the two populations. the extent thereof is not sufficient to regard them as subspecies

Die reg van die homoseksuele ouer om beheer en toesig oor 'n kind te verkry in die lig van die bepalings van die Grondwet

The problematic nature of the right of a homosexual parent to vest custody over a child is biarticulated: the nature and extent of custody disputes as well as the issues of discrimination based on sexual orientation are relevant. Homosexual orientation is emotional and controversial, all the more when it is accompanied by custody disputes. In this context the constitutional protection given to human rights and the constitutional provisions containing constitutional values are of paramount importance. The contents of these provisions have direct consequences for custody disputes and homosexual parenthood. In the pre-constitutional dispensation, the court gave judgement in Van Rooyen v Van Rooyen 1994 2 SA 325 (W) on the awarding of access rights to a homosexual parent. With regard to the provisions of the Constitution of the Republic of South Africa 108 of 1996 and trends in relevant foreign law, the decision in the Van Rooyen case is subjected to criticism. Since the commencement of the Constitution of the Republic of South Africa 200 of 1993, no South African court has given judgement on this issue. The aim of this contribution is to set out an autochthonous frame of reference considering the provisions of the Constitution, case law and comparative foreign law in an attempt to resolve the issue under discussion.  &nbsp

Assessment of CHD-specific primers for gender determination in red-billed oxpeckers (buphagus erythrorhynchus)

Red-billed Oxpeckers Buphagus erythrorhynchus are morphologically similar and do not display distinctive phenotypic difference between males and females. The development of DNA-based gender determination techniques constituted a breakthrough in reliable sex determination in birds. Two DNA-based methods of gender determination were evaluated to determine the preferred method for the Red-billed Oxpeckers. DNA-based gender determination of the Red-billed Oxpeckers was conducted so that specific sexes could be relocated  to new release sites within South Africa. The two primer sets used were 2550F/2718R and P2/P8. When comparing the results of the two primer sets, it was determined that 17% (n = 25) of individuals that were identified as having one sex by the 2550F/2718R primer set changed their DNA gender determination when the P2/P8 primer set was used. Based on molecular evidence and the pathology results for three recorded mortalities at the National Zoological Gardens of South Africa, it was determined that the P2/P8 primer set would be preferable to the 2550F/2718R primer set for DNA gender determination of Red-billed Oxpeckers. OSTRICH 2010, 81(3): 251–25

Assessment of CHD-specific primers for gender determination in red-billed oxpeckers (buphagus erythrorhynchus)

Red-billed Oxpeckers Buphagus erythrorhynchus are morphologically similar and do not display distinctive phenotypic difference between males and females. The development of DNA-based gender determination techniques constituted a breakthrough in reliable sex determination in birds. Two DNA-based methods of gender determination were evaluated to determine the preferred method for the Red-billed Oxpeckers. DNA-based gender determination of the Red-billed Oxpeckers was conducted so that specific sexes could be relocated  to new release sites within South Africa. The two primer sets used were 2550F/2718R and P2/P8. When comparing the results of the two primer sets, it was determined that 17% (n = 25) of individuals that were identified as having one sex by the 2550F/2718R primer set changed their DNA gender determination when the P2/P8 primer set was used. Based on molecular evidence and the pathology results for three recorded mortalities at the National Zoological Gardens of South Africa, it was determined that the P2/P8 primer set would be preferable to the 2550F/2718R primer set for DNA gender determination of Red-billed Oxpeckers. OSTRICH 2010, 81(3): 251–25

Diversity in the Toll-Like Receptor Genes of the African Penguin (Spheniscus demersus)

The African penguin, Spheniscus demersus, is listed as Endangered by the IUCN Red List of Threatened Species due to the drastic reduction in population numbers over the last 20 years. To date, the only studies on immunogenetic variation in penguins have been conducted on the major histocompatibility complex (MHC) genes. It was shown in humans that up to half of the genetic variability in immune responses to pathogens are located in non-MHC genes. Toll-like receptors (TLRs) are now increasingly being studied in a variety of taxa as a broader approach to determine functional genetic diversity. In this study, we confirm low genetic diversity in the innate immune region of African penguins similar to that observed in New Zealand robin that has undergone several severe population bottlenecks. Single nucleotide polymorphism (SNP) diversity across TLRs varied between ex situ and in situ penguins with the number of non-synonymous alterations in ex situ populations (n = 14) being reduced in comparison to in situ populations (n = 16). Maintaining adaptive diversity is of vital importance in the assurance populations as these animals may potentially be used in the future for re-introductions. Therefore, this study provides essential data on immune gene diversity in penguins and will assist in providing an additional monitoring tool for African penguin in the wild, as well as to monitor diversity in ex situ populations and to ensure that diversity found in the in situ populations are captured in the assurance populations

SNP discovery and characterisation in White Rhino (Ceratotherium simum) with application to parentage assignment

Abstract The white rhino is one of the great success stories of modern wildlife conservation, growing from as few as 50-100 animals in the 1880s, to approximately 20,000 white rhinoceros remaining today. However, illegal trade in conservational rhinoceros horns is adding constant pressure on remaining populations. Captive management of ex situ populations of endangered species using molecular methods can contribute to improving the management of the species. Here we compare for the first time the utility of 33 Single Nucleotide Polymorphisms (SNPs) and nine microsatellites (MS) in isolation and in combination for assigning parentage in captive White Rhinoceros. We found that a combined dataset of SNPs and microsatellites was most informative with the highest confidence level. This study thus provided us with a useful set of SNP and MS markers for parentage and relatedness testing. Further assessment of the utility of these markers over multiple (> three) generations and the incorporation of a larger variety of relationships among individuals (e.g. half-siblings or cousins) is strongly suggested

Survival and population dynamics of the Marabou Stork in an isolated population, Swaziland

Investigating the ecology of long lived birds is particularly challenging owing to the time scales involved. Here an analysis is presented of a long term study of the survival and population dynamics of the marabou stork (Leptoptilos crumeniferus), a wide ranging scavenging bird from Sub-Saharan Africa. Using resightings data of tagged nestlings and free flying birds we show that the stork population can be divided into three general life stages with unique survival probabilities and fecundities. Fecundity of the storks is inversely related to rainfall during their breeding season. Corroborative evidence for a metapopulation structure is discussed highlighting the impact of the Swaziland birds on the ecology of the species in the broader region. The importance of tag loss or illegibility over time is highlighted. Clearly, any attempt at conserving a species will require a detailed understanding of its population structure, of the sort examined here