Abstract:
The knowledge of the genetic relationship and admixture among neighbouring
populations is crucial for conservation efforts. The aim of this study was to analyze the
genetic diversity and population structure of the indigenous sheep in Kenya using 15
microsatellite markers. Blood samples from 582 individuals were obtained and
genotyped across 15 microsatellite markers. Values of expected heterozygosity and
Mean number of alleles ranged from 0.596 to 0.807 and 6.67 to 9.33 respectively
depending on the population. Most of the investigated populations showed a significant
heterozygote deficiency caused by a moderately high level of inbreeding indicated by fIS
(0.109). The observed genetic diversity was found to be high in the nucleus flocks as
opposed to those kept by the famers. Genetic differentiation between breeds was
moderate (θST = 0.101) but significant. The genetic distances obtained reflect the
historical knowledge of these breeds and some patterns of ancestral and recent gene flow
between neighbour populations arise. According to genetic relationships, multivariate
and structure analyses four population clusters were detected which were majorly based
on geographical proximity and interbreeding among the populations. These results
indicate that the levels of admixture observed warrant the institution of conservation
measures if the genetic purity and integrity of the indigenous sheep in Kenya is to be
maintained. However, a more encompassing study that includes all the regions in the
country known to harbor the indigenous sheep, as well as a larger sample size with more
microsatellite markers genotyped is necessary to enable a comprehensive understanding
of the dynamics of genetic introgression in the country.
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