The black rhino sanctuaries system has played a key role in repopulating and starting new subpopulations in Kenya. If this system is efficiently managed it may save the black rhinoceros from local extinction. Understanding the genetic status of endangered species is the most elemental sine qua non of animal breeding and conservation. It is therefore important to determine the genetic diversity of black rhino populations, especially of nucleus breeding populations that are used as a source of individuals for translocation and supplementation programs. We assessed the genetic diversity of one of the pioneer breeding subpopulations of the black rhino Diceros bicornis in Kenya using a mitochondrial DNA D-loop region. We then compared this subpopulation with the entire Kenyan population to determine its status vis-a-vis the Kenya pooled population and determine the possible sources/relationships of the founder individuals. In the 469-bp D-loop region we analyzed, 7.11% of the sites were variants, contributing to 18 distinct haplotypes. Estimates of genetic diversity using haplotype and nucleotide diversity metrics showed that the Lake Nakuru National Park subpopulation has a slightly lower genetic diversity when compared with that of the pooled Kenya population. The phylogenetic tree revealed that Lake Nakuru National Park founder individuals were probably sourced from multiple subpopulations. The dendrogram and the principal coordinate analysis plot indicated that the Maasai Mara subpopulation is not a distinct subpopulation, as had been suggested previously. Our results provide baseline genetic data for the Lake Nakuru National Park breeding subpopulation and valuable information for translocation/supplementation programs.

Fresh water snails of genus Biomphlaria, Bulinus and Ocomelinia are important vectors for human schistosomiasis. Human contact patterns with water infested with cercaria are important factors in transmission of schistosomiasis and these conditions are associated with tropical climate wetlands. However, some snail strains within the genera that transmit cercaria are resistant to infection, providing means where these traits can be harnessed for biological control. PCR rDNA probes were used to determine miracidia/cercaria infected Biomphalaria snail isolates within Kenya. The derived sequences together with similar Genbank datasets were applied in phylogenetic analysis. PCR results showed that susceptibility/resistance trait occurs in proportion of the field sampled snails and also those maintained in laboratory culture. Phylogenetic analysis of sampled snails in this study together with composite dataset of similar rDNA sequences across Africa showed that Biomphalaria spp population structure is composed of distinct monophyla lineages and clusters of closely related isolates or clones. Further, the analysis indicated that nomenclature of Biomphalaria spp. classification needs revision. This provides evidence for resistance to cercaria transmission in some isolates of Biomphalaria spp. within Kenya but the trait does not cluster together in phylogenetics that is based on rDNA gene.

SummaryKenya indigenous goat breeds (Capra hircus) have not been accurately described. Therefore, there is threat of erosion of unique genotypes such as those associated with adaptability and disease resistance, through indiscriminate crossbreeding. The Kenyan goats classification based on phenotype/morphology identifies three breeds: Small East African (SEA) goats, the Galla goat and crosses of SEA and the Galla. In the present study, we sampled goats from two main geographic regions of Kenya with pastoralist communities, the Maasai and Somali/Boran. DNA was extracted from whole blood and polymerase chain reaction amplified using primers flanking a fragment of Cytocrome-b and D-loop regions of mitochondria DNA. The sequences derived were analysed both within Kenya goat populations and also compared with phylogeographic-related datasets. These data show that the majority of Kenyan indigenous goats are not distinct and their genetic structure is very diverse; however, distinct haplogroups were present. Genetic diversity showed weak positive in Tajima D test for Kenyan indigenous goats, while the Iberian/Mediterranean/Middle-East dataset had a more pronounced negative value indicating that the two populations are under different selection pressure. These analyses enabled phylogenetic relationships between and within species and the comparisons of local goats to related breeds geographically. The information can be applied management of conservation-guided breeding programmes by crossing the indigenous breed's unique genes with high productivity traits from another source.

Phylogenetic relationships among and genetic variability within 60 goats from two different indigenous breeds in Narok and Isiolo counties in Kenya and 22 published goat samples were analysed using mitochondrial control region sequences. The results showed that there were 54 polymorphic sites in a 481-bp sequence and 29 haplotypes were determined. The mean haplotype diversity and nucleotide diversity were 0.981 ± 0.006 and 0.019 ± 0.001, respectively. The phylogenetic analysis in combination with goat haplogroup reference sequences from GenBank showed that all goat sequences were clustered into two haplogroups (A and G), of which haplogroup A was the commonest in the two populations. A very high percentage (99.90%) of the genetic variation was distributed within the regions, and a smaller percentage (0.10%) distributed among regions as revealed by the analysis of molecular variance (amova). This amova results showed that the divergence between regions was not statistically significant. We concluded that the high levels of intrapopulation diversity in Isiolo and Narok goats and the weak phylogeographic structuring suggested that there existed strong gene flow among goat populations probably caused by extensive transportation of goats in history.

While residing in the mammalian bloodstream, adult schistosomes consume large quantities of glucose and metabolize it to lactic acid. The accumulating load of this end product in the parasite tissue lowers the cellular pH, hence the need for a system to flux it out to avoid compromising metabolic processes. In the present study, we assayed the rate of secretion of lactic acid into the culture medium by adult worms and schistosomula. When cultured in RPMI-1640 medium containing 2 mM glucose, the rate of lactic acid secretion was 0.022 mmol/mg dry wt/h and the secretion increased to 0.043 mmol/mg dry wt/h when they were cultured in medium containing 10 mM glucose. Continuous culture of the parasite resulted in accumulation of lactic acid in the media to about 10 mM whereupon further increase was markedly slower. The media pH in such extended cultures had dropped from an initial 7.4 to about 6.7. In separate experiments, schistosomula were found to be sensitive to >10 mM lactic acid in medium. These results suggest that drugs that inhibit transport of lactic acid may have therapeutic potential against schistosomes. Keywords: schistosomes, metabolism, glucose, lactic acid Journal of Tropical Microbiology and Biotechnology Vol. 2(1) 2006: 31−36