Use of microsatellite markers to assign goats to their breeds.

We investigated the potential of 17 microsatellite markers for assigning Saudi goat individuals to their breeds. Three local breeds, Bishi, Jabali, and Tohami were genotyped using these markers, and Somali goats were used as a reference breed. The majority of alleles were shared between the breeds, except for some that were specific to each breed. The Garza-Williamson index was lowest in the Bishi breed, indicating that a recent bottleneck event occurred. The overall results assigned the goat individuals (based on their genotypes) to the same breeds from which they were sampled, except in a few cases. The individuals' genotypes were sufficient to provide a clear distinction between the Somali goat breed and the others. In three factorial dimensions, the results of a correspondence analysis indicated that the total variation for the first and second factors was 48.85 and 31.43%, respectively. Consequently, Jabali, Bishi, and Tohami goats were in separate groups. The Jabali goat was closely related to the Bishi goat. Somali goats were distinguished from each other and from individuals of the other three goat breeds. The markers were successful in assigning individual goats to their breeds, based on the likelihood of a given individual's genotype.

Genetic distances and phylogenetic trees of different Awassi sheep populations based on DNA sequencing.

This study aimed to estimate evolutionary distances and to reconstruct phylogeny trees between different Awassi sheep populations. Thirty-two sheep individuals from three different geographical areas of Jordan and the Kingdom of Saudi Arabia (KSA) were randomly sampled. DNA was extracted from the tissue samples and sequenced using the T7 promoter universal primer. Different phylogenetic trees were reconstructed from 0.64-kb DNA sequences using the MEGA software with the best general time reverse distance model. Three methods of distance estimation were then used. The maximum composite likelihood test was considered for reconstructing maximum likelihood, neighbor-joining and UPGMA trees. The maximum likelihood tree indicated three major clusters separated by cytosine (C) and thymine (T). The greatest distance was shown between the South sheep and North sheep. On the other hand, the KSA sheep as an outgroup showed shorter evolutionary distance to the North sheep population than to the others. The neighbor-joining and UPGMA trees showed quite reliable clusters of evolutionary differentiation of Jordan sheep populations from the Saudi population. The overall results support geographical information and ecological types of the sheep populations studied. Summing up, the resulting phylogeny trees may contribute to the limited information about the genetic relatedness and phylogeny of Awassi sheep in nearby Arab countries.

Genetic relatedness between Ardi, Black Bedouin and Damascus goat breeds.

The present study aimed to analyze genetic relatedness and differentiation of common native goat populations in some countries of the Middle East. The populations were Ardi, Black Bedouin, and Damascus goats in the Kingdom of Saudi Arabia, Jordan, and Syria, respectively. Domesticated goats of the Middle East are mostly related to common ancestors, but there is limited molecular genetic evidence. Four microsatellite DNA markers were genotyped in 89 individuals of the three populations using an automated genetic analyzer. Ardi, Black Bedouin, and Damascus goats exhibited high average allele number and expected heterozygosity of 8.25, 9, and 7.25, and 0.750, 0.804, and 0.779, respectively. F-statistics for population differentiation showed 6.0% of total genetic variation, whereas 94.0% as differentiation between individuals within all populations. The least varied within populations was Ardi goats, then Damascus goats and finally Black Bedouin goats. Furthermore, the Damascus goat population was more differentiated from Black Bedouin goats than from Ardi goats. On the other hand, there was strong evidence of admixture between the majority of Ardi and Black Bedouin goat individuals but little with those of Damascus goats. Genetic distance between Ardi and Black Bedouin goats was the shortest, whereas it was the longest between Ardi and Damascus goats. The phylogenetic tree clearly revealed the expected degree of differentiation in the three populations. From a genetic conservation point of view, it is recommended to maintain the biodiversity of these distinct populations in case genetic migration of genetic resources and genetic conservation are absent.