Genetic Diversity in Four Populations of Nguni (Zulu) Sheep Assessed by Microsatellite Analysis

Abstract

Zulu sheep are found mainly in the rural KwaZulu-Natal province and the numbers are declining due to indiscriminate inbreeding. There is thus a need for phenotypic and genetic characterisation as a first phase for planning conservation strategies. Zulu sheep populations sampled were from Makhathini research station (MS) (n=33), University of Zululand (UZ) (n=21), a community at KwaMthethwa (KM) (n=32) and from Msinga (EM) (n=33). One European breed Appenninica (AP) was used as out group. Microsatellite analysis using 29 microsatellite loci was used in this study. Among the Zulu sheep, the mean number of alleles per locus was the lowest (3.86) in UZ and the highest (6.24) was realised in EM. The mean values of observed and expected heterozygosity were 0.57 and 0.61, respectively. Neighbour-joining tree showed two main Zulu sheep clusters: the UZ, KM and MS sheep populations clustered together and the second cluster included only representatives from the EM population. The STRUCTURE analysis showed that KM, AP and EM were founded in separate clusters, whereas UZ and MS clustered together. The study demonstrated that there was a common origin of the population from the research stations (MS and UZ populations). It also demonstrated that the EM had a different history for the other three populations. This work suggests that exchange of rams could be useful in reducing inbreeding when considering conservation breeding programmes.

Contribution of microsatellites markers in the clarification of the origin, genetic risk factors, and implications for conservation of Tunisian native sheep breeds

“…The mean PIC across all loci was 0.791 ± 0.091, ranging from 0.546 (OarAE129) to 0.905 (OarCP49). These values are comparable to those recently recorded by Ben Sassi-Zaidy et al (2014a,b) in the first investigation of Tunisian sheep and higher than those estimated in the Zulu South African sheep (Kunene et al, 2014) and in the Kenyan sheep populations (Mukhongo et al, 2014). In the overall population, the homozygote excess (F IT ) of 0.118 ± 0.091 was mainly due to a significant homozygote excess within breeds (F IS = 0.112 ± 0.091) rather than genetic differentiation among them since the F ST index was limited to 0.007 ± 0.008 (P< 0.001).…”

“…Lowest heterozygosity and greatest inbreeding coefficient (F IS ) values exhibited by CRO population are shown in bold font. In general, the analyzed populations showed reasonably high allelic richness and heterozygosity values compared to some African (Soma et al, 2012;Kunene et al, 2014;Mukhongo et al, 2014), European (Salamon et al, 2014), Asian (Al-Barzinji et al, 2011;Blackburn et al, 2011b), and American (Blackburn, et al, 2011a;Souza et al, 2012;Ferreira et al, 2014) sheep breeds. The lowest values of AR and heterozygosity were observed in the crossbred population in which H O was notably lower than the H E (Table 2).…”

Morphological differentiation amongst Zulu sheep populations in KwaZulu-Natal, South Africa, as revealed by multivariate analysis

“…The smaller size observed in Empangeni sheep could be attributed to a probable inbreeding depression even if that was not highlighted in a previous molecular study carried out on the same population (Kunene et al, 2014); flocks in this area are in fact reported to have been founded upon small initial stock; which has resulted in mating of closely related animals exacerbated by prevalent uncontrolled mating system in these areas (Mavule, 2012). Kunene et al (2007) Kosgey et al (2008) who indicates that good management practices can bring about a remarkable improvement in productivity of the presumed less productive indigenous genetic resources.…”

“…Morphological diversity is a good reflector of ecological selection regimes and history of a breed (González et al, 2011). In addition, phenotypes are an expression of genetic characteristics, modified by environmental conditions and variance in both genetics and environment may affect phenotypic variance (Yakubu et al, 2010;Kunene et al, 2014). It is in the context of these assertions that this study exclusively depended on morphometric measurements and geographic locations to unravel the characteristic of genetic diversity amongst Zulu sheep populations, which is most relevant for managing the present and future genetic diversity of the breed.…”

Studies on Genetic Variability in Nellore Brown Sheep Using Microsatellite Markers

“…Arranz et al (1998Arranz et al ( , 2001; Tomosco et al (2002); Qanbari et al (2007); Karthickeyan et al (2008); Khan et al (2009) and Molaee et al (2009); Nanekarni et al (2011) and Tolone et al (2012) used salting out method proposed by Miller et al (1988) in their studies, whereas magic buffer method suggested by David and Olivier (2005) was adopted by Al-Barzinji et al (2011). Kit method was used by Uzun et al (2006); Dalvit et al (2008); Santos-Silva et al (2008); Lasagna et al (2009); Poissant et al (2009); Kevorkian et al (2010); Khaldi et al (2010); Nanekarani et al (2010); Dashab et al (2011); Kaweeka et al (2011); Musthafa et al (2012); Ghazy et al (2013); Al-Atiyat et al (2014) and Kunene et al (2014) for isolation of DNA from the blood samples.…”