Microsatellite-Based Genetic Structure and Diversity of Local Arabian Sheep Breeds

Abstract

The genetic diversity of the sheep breeds in the Arab countries might be considered to be a mirror of the ecology of the region. In this study, the genetic structure and diversity of sheep breeds from Saudi Arabia (Harri, Najdi, Naemi, Arb, and Rufidi) and Awassi sheep from Jordan as an out-group were investigated using 19 microsatellites. All the breeds had high intra-population genetic diversity expressed as allelic number (7.33) and richness (2.9) and, expected heterozygosity (0.77). Structure analysis revealed three main gene pools underlying the ancestral genetic diversity of the study populations. The first pool had Harri, Najdi, and Rufidi breeds; the second had Naemi and Awassi breeds, and the third had the Arb breed which was significantly differentiated from the other breeds. Factorial correspondence analysis lent further support to the presence of the three gene pools. Although the outgroup Awassi sheep was more clearly differentiated, it still genetically close to Naemi sheep. The differentiation of the Arb breed could have been resulted from geographic and reproductive isolation. On the other hand, the genetic structure of the other two gene pools could be the result of the past and recent gene flow between individuals reared in the region known to be the center for animal husbandry and trading until the current time.

Genetic Diversity of Montenegrin Local Sheep Breeds Based on Microsatellite Markers

“…The population means of He and uHe were 0.723 and 0.733, respectively. These results are in accordance with results obtained for the group of autochthonous breeds from the Balkan Peninsula [ 12 ], Kazakh sheep breeds [ 17 ], some Croatian local breeds that belong to the group of coarse-wool Pramenka breeds [ 45 ], as well as Jordan and Arabian sheep breeds [ 43 , 46 ]. A higher diversity of the sheep population in terms of the average Ho and PIC was reported for 12 Algerian sheep breeds [ 18 ] and 14 Iran sheep breeds [ 47 ], and a lower diversity of the sheep population was obtained by many researchers [ 15 , 19 , 41 ].…”

“…The presence of null alleles is usually defined as non-amplifying alleles due to mutations at PCR primer sites, which have been associated with heterozygous deficits and causes overestimation of F ST and genetic distance values. Only loci with a value of null alleles higher than 0.2 are considered potentially problematic for calculations of observed heterozygosity and inbreeding coefficients [ 18 , 45 , 46 ]. In our study, the frequency of null alleles was higher than 0.2 for 13 marker loci.…”

A Comparative Study of Sheep Breeds: Fattening Performance, Carcass Characteristics, Meat Chemical Composition and Quality Attributes

“…This may be attributed to the common ancestry of the three breeds. In a study ( 41 ) reported that Harri and Najdi breeds were categorized within the same gene pool based on a structure analysis. Moreover, a second study that evaluated the genetic diversity of these three breeds using microsatellite markers, concluded there was low population differentiation among the three sheep populations ( 42 ).…”

Study of Genetic Diversity Using Microsatellite Markers in Iraqi Sheep Breeds

“…Also the results reported by AL-Brkat (5) who studied the Awassi sheep in southern Iraq using microsatellite markers and found it was have a genetic diversity. The study conducted by Al-Atiyat et al (3) in Saudi Arabia on five breeds of sheep, including the breed of Naimi and foreign breed (Awassi Jordanian sheep) to determine the structure and genetic diversity of these breeds using microsatellite that basis of our work, in their work, they obtained that the BM1329 had a genetic diversity, as the Al-Naimi breed of Saudi Arabian showed the presence of 8 YLs and the Awasi breed of Jordanian contained 4 YLs of this microsatellite and that these two breeds were closer together in terms of structure hereditary breeds from the other breeds despite the different geographical location. The results of the BM1329 study indicate that there are variations in the number and size of alleles, which can be used in the study of genotypes and the relationship between individuals per breed and between breeds.…”