Genetic diversity of the Cameroon Western Highlands’ Djallonke sheep assessed by Mitochondrial d-loop

Abstract

Indigenous livestock resources are strategic in the socio-economic of rural agricultural systems to ensure food and nutritional security in resource-poor countries. In Cameroon, small ruminant farming significantly contributes to food security and income generation. Given its great ecological variety, Cameroon hosts a large genetic diversity of sheep, but the knowledge on these is scanty. In order to contribute to a better understanding of the genetic diversity of Cameroon's Ovine genetic resources for their better use and conservation, an analysis of the Djallonke sheep genetic diversity based on the D loop of the ovine mitochondrial DNA (mtDNA) was performed on the highlands of West Cameroon Djallonke breed. To achieve this, analyses of 16 sequences of a 989bp fragment of the mtDNA D-loop region from the population were conducted in conjunction with previously published sequences from African, European, Japanese and Chinese ovine genotypes. Fourteen haplotypes were observed with a high mean haplotype diversity of 1.0000±0.027, nucleotide diversity (π) of order of 0.11082±0.062. The average nucleotide difference between sequences taken two by two was 62.945. Population specific FST indices showed a negative and significant result for the whole data set. The phylogenetic tree indicates that the mitochondrial lineages of these sheep breeds originated from a common source, the Haplogroup B. This confirms the hypothesis that the domestication of African sheep was carried out in successive waves from Asia. The results of this study contribute to the knowledge of Cameroon sheep breeds and the plan conservation programs on Djallonke sheep.