A preliminary biochemical genetic survey of four South African painted reed frog (Hyperolius marmoratus) populations

Allozyme electrophoresis was used to evaluate genetic variability in painted reed frog (Hyperolius marmoratus) populations from the Northern Province and the Eastern Cape. Sixteen protein-encoding loci were resolved, of which seven displayed allelic polymorphism. Average heterozygosity (H) values in two permanent H. m. taeniatus populations from the Northern Province (7.9% and 6.3%) did not differ substantially from each other nor from the geographically distant Eastern Cape H. m. verrucosus (9.1%). An isolated Northern Province H. m. taeniatus population displayed more polymorphism than any other group with H=14.1%, which can probably be attributed to the periodic influx of reed frogs following dry periods. Genetic distances and gene diversity (FST) values conformed with expected values for conspecific populations. The results attained concur with the hypothesis of increased genetic heterogeneity among populations of small and relatively sedentary animals

Genetic divergence between two clinostomatid fish endoparasites, inferred from allozyme and RAPD data

We used allozyme and RAPD-derived data to analyse genetic divergence between Clinostomum complanatum and Neutraclinostomum intermedialis. Allozyme results showed an average heterozygosity of 4.04% in the former species and 0.7% in the latter, and with extreme divergence between the two species with fixation for alternative alleles in five out of 13 loci screened. Genetic distance and fixation index values between the two species were 0.921 and 0.920 respectively. Results from random amplified polymorphic DNA (RAPD) fingerprinting revealed additional genetic diversity within species (genetic similarities 0.742 and 0.829) and confirmed considerable divergence between the two clinostomatid species (genetic similarity 0.559). The results obtained suggest reproductive isolation between the two species and convincingly nullify earlier attempts to synonymise them

Performance trait analysis and genetic diversity of the SA Boerperd

This study determined the occurrence and frequency of mutations that influence performance traits in the SA Boerperd horse and evaluated genetic diversity within the breed. Two gait-associated and two heightassociated mutations were investigated. Seventeen microsatellite markers were genotyped for 363 horses and used to assess genetic diversity. The C-allele of the height-associated single nucleotide polymorphism (SNP) BIEC2_808543 was present in 5% of the population, and 57% of the horses possessed the A-allele of BIEC2_1105377, which has been also associated with height. However, these SNPs did not significantly affect measured phenotypic height within the breed. The minor alleles for SNP DMRT3_Ser301STOP and BIEC2_620109, which have been associated with gaitedness, occurred with frequencies of 0.105 and 0.091, respectively, within the breed. The microsatellite data revealed observed heterozygosity (Ho = 0.679) to be similar to that found 15 years ago, while the level of inbreeding had decreased from 8.4% to 3.2%. However, allelic richness had declined from 4.212 to 3.804. Analysis of the population structure revealed that two distinct founder populations have contributed to the present-day breed. Compared with nine European breeds, the SA Boerperd had above average levels of heterozygosity and a high number of private alleles (17.6%). A high degree of variation remained in the SA Boerperd, despite selective breeding, and levels of inbreeding were still manageable. Results obtained in this study can be used by SA Boerperd breeders to develop the breed, while simultaneously conserving its genetic potential. Keywords: gaitedness, height, horses, inbreeding, selective breedin

Allozyme variation in two populations of the Mopane worm, Imbrasia belina (Saturniidae), and the effect of developmental stage and staggered generations

Imbrasia belina is utilised as a food item by certain ethnic groups of southern Africa, but little is known of the genetic structure of this resource. The aims of this study were to determine whether the limited flight ability of moths has an effect on gene flow between two geographically distant I. belina populations, whether there are gene expression differences between moths, worms and pupae and whether staggered generations have different genotypic expressions. Gene products of 19 protein-coding loci from moths collected at two locations, one of which included two staggered generations, were analysed by horizontal starch gel electrophoresis. High levels of polymorphism (42% and 47%) and heterozygosity (0.182 to 0.210) were present in all groups. There were developmental constraints on the expression of the phosphoglucomutase enzyme coding locus, and only allozyme and not isozyme differences between individuals from the various developmental stages were found at other loci. Although the groups displayed a large amount of variation, little differentiation and a large amount of gene flow were observed between them. Results indicate that the genetic diversity of I. belina populations is relatively high. The February-hatching Messina group is recommended for commercial utilisation due to the large amount of genetic variation in this population. (South African Journal of Animal Science, 2001, 31(1): 15-24

Genetic variability in a population of Letelle sheep in South Africa

The purpose of the study was to gain insight into the genetic variability of the Letelle sheep breed, a breed that has been managed as a closed population for 90 years, with no new genetic material being permitted into the breed. The Letelle is a South African developed dual-purpose sheep breed and is classified as a Merino type with a Spanish Merino origin. The breed exhibits good fine wool characteristics and yields high-quality mutton. Line-breeding, family-breeding, and inbreeding are applied, and multiple sire matings are practised to prevent a sire from having a large influence on the national flock. Ear samples were collected from 10 animals each from 10 commercial and 11 seed-stock flocks and genotyped using 17 microsatellite markers. Unbiased heterozygosity ranged from 0.58 to 0.68 and the observed heterozygosity from 0.52 to 0.65. The estimated effective population size (Ne) was 228.2 - 321.9. Results from analysis of molecular variance (AMOVA), a Bayesian assignment test, and a neighbour-joining (NJ) tree suggested that no genetic sub-structure existed within this population and that the seed-stock and commercial flocks could be regarded as one genetic population. The average within flock (FIS) and within breed (FIT) inbreeding coefficients were 10.1% and 14.5%, respectively. Despite the level of inbreeding, levels of genetic diversity were moderate and potentially provide opportunities for future selection and adaptation. Further testing could identify flocks in which conservation management is required as well as those with high genetic variability, which would provide the best reservoir for selection to adapt to future climatic challenges.Keywords: genetic distance, inbreeding, microsatellite markers, population structur

Ulcerative pododermatitis in free-ranging African elephant (Loxodonta africana) in the Kruger National Park

The occurrence of severe lameness in adult African elephant bulls in a shrub Mopane (Colophospermum mopane) ecosystem was investigated. Large ulcers in the soles of at least one front foot were seen in each of the recorded cases. Microscopically, the lesion can be described as a severe, chronic-active, ulcerative, bacterial pododermatitis (complicated by hypersensitivity/septic vasculitis). A variety of bacteria were isolated from these lesions as well as from regional lymph nodes. Streptococcus agalactiae was the most consistent isolate, while Dichelobacter nodosus, the only organism known to be involved with foot disease in domestic ruminants, was isolated from two cases. Contributory factors such as body mass, portal of entry and origin of potential pathogens may have predisposed to the development of the lesions.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park

A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7 500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53 %), 18 of 139 (13%) and seven of 33 (21 %) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EMC virus in rodents, and the occurrence of the outbreak of disease in elephants.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Genetic diversity and population structure of the African catfish, <i>Clarias gariepinus</i> (Burchell, 1822) in Kenya: implication for conservation and aquaculture

African catfish, Clarias gariepinus, is an important species in aquaculture and fisheries in Kenya. Mitochondrial D-loop control region was used to determine genetic variation and population structure in samples of C. gariepinus from 10 sites including five natural populations (Lakes Victoria (LVG), Kanyaboli (LKG), Turkana (LTA), Baringo (LBA) and Jipe (LJP), and five farms (Sangoro Aquaculture Center (SAN), Sagana Aquaculture Centre (SAG), University of Eldoret Fish Farm (UoE), Kibos Fish Farm (KIB), and Wakhungu Fish Farm (WKU)) in Kenya. Similarly, samples from eight localities (four natural populations: LVG/LKG, LTA, LBA, and four farmed: SAN, SAG, KIB, UoE) were genotyped using six microsatellite DNA loci. For the D-loop control region, samples from natural sites exhibited higher numbers of haplotypes and haplotype diversities compared to farmed samples, and 88.2% of haplotypes were private. All except LJP and LTA shared haplotypes, and the highest number of shared haplotypes (8) was detected in KIB. The 68 haplotypes we found in 268 individuals grouped into five phylogenetic clades: LVG/LKG, LTA, LBA, LJP and SAG. Haplotypes of farmed C. gariepinus mostly have haplotypes typical of LVG/LKG, and some shared haplotypes of the LBA population. Microsatellite analysis showed farmed samples have higher numbers of alleles than natural samples, but higher observed and expected heterozygosity levels were found in samples of natural populations. Fifteen pair-wise comparisons had significantly different FST values. All samples were in Hardy-Weinberg equilibrium. Samples from the eight localities grouped into four genetic clusters (LVG/LKG, LTA, LBA and SAG), indicating genetically distinct populations, which should be considered for aquaculture and conservation

Enzyme structure, enzyme function and allozyme diversity in mammals: trends from South African population genetic studies

In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be less polymorphic. In this paper I review most of the published papers on allozyme variability in southern African mammals, and correlate heterozygosity values with enzyme quaternary structure and the perceived importance of enzymes. Results provide support for the hypothesis of a linkage between enzyme quaternary structure and diversity. No association between enzyme function and heterogeneity was, however, observed.Keywords: heterozygosity, allozyme, quaternary structure, enzyme functio