Genetic diversity in Zimbabwean Sanga cattle breeds using microsatellite markers

Abstract

Zimbabwe's smallholder land-based livelihoods are dominated by the three local Sanga cattle breeds, namely Mashona, Tuli, and Nkone. A study was carried out to determine genetic diversity and differentiation among conservation populations of these breeds using 16 bovine-specific microsatellite markers. These markers included BM1818, BM1824, BM2113, CSRM60, CSSM66, ETH10, ETH225, ETH3, ILST006, INRA23, RM067, SPS115, TGLA122, TGLA126, TGLA227, and TGLA53. All marker loci contributed to breed differentiation based on the infinitesimal model (F ST ), with the most powerful markers being CSSM66 (25%), ETH225 (20.6%), and TGLA122 (13.8%) and the least powerful being RM067 (0.7%), BM1824 (1.0%), and ETH10 (1.1%). Three marker loci (BM1824, ETH225, and ETH3) revealed significant deviations from Hardy-Weinberg equilibrium (HWE) proportions. A total of 119 alleles were observed, ranging from 4 to 11 and averaging 7.4 alleles per locus. Thirty-four of these alleles were unique to specific breeds. Mean (Na) and effective (Ne) numbers of alleles were 5.167 ± 0.302 and 3.462 ± 0.163 alleles per locus, respectively, with no significant differences between breeds. Observed heterozygosity (H O ) (0.73) was higher than expected heterozygosity (H E ) (0.71), revealing that breeds were in HWE. Global F-statistics F IT , F ST , and F IS gave mean values of 0.059, 0.084 and -0.028, respectively. Overall breed genetic differentiation was moderate (F ST = 8.4%) and significant (P <0.001). Multivariate analyses separated the three breeds completely, and revealed that most of the genetic variation was within breed (92%). The analyses revealed that a significant amount of variation is maintained in these breeds and that they are distinct genetic entities that may be considered for utilization or conservation. ______________________________________________________________________________________

Genetic Diversity of the N’Dama Breed in Mali Using SSR Markers

“…These average values of PICs were close to those of current study where only five SSRs were used in common (MM12, INRA63, ILSTS011, ILSTS005, and BM1824). Furthermore, Gororo et al [28] found PIC values close to those of actual study with TGLA53 and TGLA 122 using 16 SSR on three breeds from Zimbabwe. The PIC value of INRA37 reported by Harton and Angus [29] on two breeds was lower than that of current founding.…”

“…Several genetic diversity studies have been conducted on cattle breeds across the world [4][5][6][7]. In Africa, Goudarzi et al [7] studied genetic variability of 201 individuals of the Somba cattle race from Benin and Togo with 33 microsatellite markers whereas, Gororo et al [28] study's was about 50 Sanga cattle race from Zimbabwe using 16 SSRs. In Senegal, N'diaye et al [5] evaluated the genetic diversity of 120 cattle composed of four races from Senegal including N'Dama race using 12 SSR markers.…”

Strategies for Sustainable Use of Indigenous Cattle Genetic Resources in Southern Africa

“…The observed small genetic differentiation (F ST = 4.8%) is a clear indication of admixture among these ecotypes with clear separation where a Nguni population was subjected to selection linked to the geographic area and specific ethnic groups [17]. In Zimbabwe, Gororo et al [23], using microsatellite markers, observed significant variation between the Mashona, Nkone, and Tuli and concluded that they are distinct breeds. Kotze et al [18] and Bessa et al [19] showed that the Bovines of Tete, Angone, and Landim of Mozambique are genetically related with the former being an admixture between the latter two.…”

“…South Africa leads in this field owing to advanced sustainable programmes of recording for genetic improvement of cattle breeds [15,17,[20][21][22]. Few studies have been conducted in Zimbabwe [23], Mozambique [18,19], and Tanzania [16].…”

“…Overall, in the SADC region, farmers, breeders, breed societies, government research institutes, and universities have been involved in in situ conservation of cattle genetic resources. According to Nyamushamba et al [7] and Gororo et al [23], the cattle populations of Mashona, Nkone, and Tuli breeds are kept at various research institutes in Zimbabwe (i.e., Henderson, Matopos, Makoholi, and Grasslands). In Malawi and Mozambique, the Malawi Zebu and the Landim are reared at Chitedze Agricultural Research Station and the Institute of Animal Production, respectively [7,18].…”