Genetic diversity and differentiation of 12 eastern Adriatic and western Dinaric native sheep breeds using microsatellites

Abstract

Nuclear genetic diversity and differentiation of 341 sheep belonging to 12 sheep breeds from Croatia and Bosnia and Herzegovina were examined. The aim of the study was to provide the understanding of the genetic structure and variability of the analysed pramenka sheep populations, and to give indications for conservation strategies based on the population diversity and structure information. The genetic variation of the sheep populations, examined at the nuclear level using 27 microsatellite loci, revealed considerable levels of genetic diversity, similar to the diversity found in other European indigenous low-production sheep breeds. Population-specific alleles were detected at most loci and in breeds analysed. The observed heterozygosity ranged from 0.643 (in Lika pramenka) to 0.743 (in Vlasic pramenka), and the expected heterozygosity ranged from 0.646 (in Lika pramenka) to 0.756 (in Dalmatian pramenka). Significant inbreeding coefficients were found for half of the populations studied and ranged from 0.040 (Pag island sheep) to 0.091 (Kupres pramenka). Moderate genetic differentiation was found between the studied sheep populations. The total genetic variability observed between different populations was 5.29%, whereas 94.71% of the variation was found within populations. Cres island sheep, Lika pramenka and Istrian sheep were identified as the most distinct populations, which was confirmed by the factorial analysis of correspondence and supported through a bootstrapping adjustment to correct for the difference in the sample sizes. The population structure analysis distinguished 12 clusters for the 12 sheep breeds analysed. However, the cluster differentiation was low for Dalmatian, Vlasic, Stolac and Krk pramenka. This systematic study identified Lika pramenka and Rab island sheep as those with the lowest diversity, whereas Istrian sheep and Pag island sheep had the highest. Conservation actions are proposed for Istrian, Rab and Cres island sheep, Lika and Kupres pramenka because of high estimated coefficients of inbreeding.

Microsatellite based genetic structure of regional transboundary Istrian sheep breed populations in Croatia and Slovenia

“…Herdbooks for the Croatian breeds were re-established after the Croatian War of Independence, and while LIK was affected directly by the war activities, island and peninsula breeds, such as ISTc and CRE were influenced only indirectly through the decrease of the population sizes. General genetic parameters, such as low diversity in LIK, or suspicion regarding an isolate braking effect in LIK and CRE indicated by heterozygosity estimates, are in accordance with these events (Salamon et al, 2014). ISTs has been found to be less variable at the genetic level than ISTc confirming the preliminary results (Salamon et al, 2012).…”

“…A previous study has analysed microsatellite based genetic diversity of a global Istrian population including samples from Croatia and Slovenia, as a whole, and in comparison with other autochthonous sheep breeds of Croatia (Salamon et al, 2014). In this study we present a more detailed analysis focused on the two different Istrian sheep populations to provide a scientific assessment of their current genetic structure.…”

Genetic relationships between six eastern Pyrenean sheep breeds assessed using microsatellites

“…Regardless of the approach used, most of the studies carried out are limited to a single country (Álvarez et al, 2004;Glowatzki-Mullis et al, 2009), while historical relationships among neighbouring sheep populations suggest the need of crossborder analyses (Tapio et al, 2005(Tapio et al, , 2010Cinkulov et al, 2008;Kusza et al, 2008;Salamon et al, 2014).…”

Identification of missense mutations in the PCP4 and CD109 genes to validate the effect of neutral genetic markers

“…The Istrian sheep belongs to the Pramenka type, which includes several breeds and populations of sheep of the East Adriatic region. Genetic origin of these sheep was traced by Ferencakovic et al (2013), who reported a surprisingly high number of mitochondrial DNA haplotypes, despite the overall maternal homogeneity, while Salamon et al (2014), analyzing the genetic structure and variability of the Pramenka populations in order to give indications for conservation strategies, showed that the Istrian breed had maintained higher variability compared to other breeds (i.e. Kupres Pramenka), the distinctiveness being confirmed by the high number (10) of conserved private alleles (Salamon et al 2014).…”

“…Genetic origin of these sheep was traced by Ferencakovic et al (2013), who reported a surprisingly high number of mitochondrial DNA haplotypes, despite the overall maternal homogeneity, while Salamon et al (2014), analyzing the genetic structure and variability of the Pramenka populations in order to give indications for conservation strategies, showed that the Istrian breed had maintained higher variability compared to other breeds (i.e. Kupres Pramenka), the distinctiveness being confirmed by the high number (10) of conserved private alleles (Salamon et al 2014). Moreover, a previous study by Salamon et al (2012) who analyzed the genetic diversity of the two Istrian populations, Croatian and Slovenian, separately, reported a higher inbreeding coefficient for the Slovenian; then the higher frequencies of peculiar alleles like the G allele are not surprising, the Istrian sheep of the present study having Slovenian origin.…”