The pattern of genetic diversity of different breeds of pigs based on microsatellite analysis

One of the main tasks of genetics and animal breeding is the assessment of genetic diversity and the study of genetic relationships between different breeds and populations using molecular genetic analysis methods. We analysed the polymorphism of microsatellites and the information on the state of genetic diversity and the population structure of local breeds in Russia: the Kemerovo, the Berkshire, the Liven, the Mangalitsa, and the Civilian; in the Republic of Belarus: the Large White and the Black-and-White; and in Ukraine: the White Steppe, as well as commercial breeds of imported origin of domestic reproduction: the Large White, the Landrace, and the Duroc. The materials used for this study were the tissue and DNA samples extracted from 1,194 pigs and DNA of the UNU “Genetic material bank of domestic and wild animal species and birds” of the L.K. Ernst Federal Research Center for Animal Husbandry. Polymorphisms of 10 microsatellites (S0155, S0355, S0386, SW24, SO005, SW72, SW951, S0101, SW240, and SW857) were determined according to the previously developed technique using DNA analyser ABI3130xl. To estimate the allele pool of each population, the average number of alleles (NA), the effective number of alleles (NE ) based on the locus, the rarified allelic richness (AR), the observed (HO ) and expected (HE ) heterozygosity, and the fixation index (FIS) were calculated. The degree of genetic differentiation of the breeds was assessed based on the pairwise values of FST and D. The analysis of the allelic and genetic diversity parameters of the local breeds showed that the maximum and minimum levels of polymorphism were observed in pigs of the Ukrainian White Steppe breed (NA = 6.500, NE = 3.709, and AR = 6.020) and in pigs of the Duroc breed (NA = 4.875, NE = 2.119, and AR = 3.821), respectively. The highest level of genetic diversity was found in the Large White breed of the Republic of Belarus (HO = 0.707 and NE = 0.702). The minimum level of genetic diversity was found in pigs of the imported breeds – the Landrace (HO = 0.459, HE = 0.400) and the Duroc (HO = 0.480, HE = 0.469) – indicating a high selection pressure in these breeds. Based on the results of phylogenetic analysis, the genetic origin of Large White pigs, the breeds, from which the Berkshire pigs originated, and the genetic detachment of the Landrace from the Mangalitsa breeds were revealed. The cluster analysis showed a genetic consolidation of the Black-and-White, the Berkshire, and the Mangalitsa pigs. Additionally, the imported breeds with clustering depending on the origin were characterised by a genetic structure different from that of the other breeds. The information obtained from these studies can serve as a guide for the management and breeding strategies of the pig breeds studied, to allow their better use and conservation

Genetic diversity of Ukrainian local pig breeds based on microsatellite markers

Preserving the current diversity of the living material on Earth is fundamental for the survival of future generations . A study was conducted to investigate the genetic diversity of Ukrainian local pig breeds. A total of 350 pigs representing five local pig breeds from Ukraine (Mirgorod – MIR, Poltava Meat – PM, Ukrainian Meat – UM, Ukrainian White Steppe – UWS and Ukrainian Spotted Steppe – USS) and one commercial breed (Duroc, DUR) were sampled. Twelve microsatellite loci (SW24, S0155, SW72, SW951, S0386, S0355, SW240, SW857, S0101, SW936, SW911 and S0228) were selected and belong to the list of microsatellite markers recommended by ISAG. The results indicate that there exists, in general, a high degree of genetic variability within the five Ukrainian local pig breeds. However, the genetic variability in the MIR and PM breeds was significantly lower (mean Na = 2.92–3.92; Ho = 0.382–0.411; FIS = 0.178–0.184) than in the other three Ukrainian local pig breeds – UM, UWS and USS (mean Na = 5.00–8.42; Ho = 0.549–0.668; FIS = 0.027–0.066). Thirty-four private alleles were identified among the six analyzed genetic groups which were distributed between 11 of the 12 loci. A high number of alleles typical for the breed (private alleles) was observed in Duroc pigs – 9 alleles did not occur in Ukrainian local pig breeds. The HWE test showed that all of the polymorphic loci deviated from HWE (P < 0.05) in at least one population. Loci S0355 (5), S0386 (4) and SW24 (4) presented a higher number of populations in imbalance. The mean FST showed that approximately 77.8% of the genetic variation was within-population and 12.2% was across the populations. The five Ukrainian local breeds were classified into two major groups, according to the phylogenetic tree, which was based on standard genetic distance. Overall, we found that 92.6% of the individual pigs were correctly assigned (324 out of 350) to the respective breed of origin, which is likely a consequence of the well-defined breed structure. Probabilities from the allocation test of individuals for the six pig genetic groups were estimated with Structure Harvester. In cluster 1 the highest grouping probabilities were found for the MIR (0.917) and PM (0.750) breeds. Local breeds UM (0.824) and USS (0.772) were grouped in cluster 2. Cluster 3 was related to the local pig breed USW (0.873). Cluster 4 presented high allocation probabilities for the commercial pig breed Duroc (0.924). The obtained results are important for the future conservation of Ukrainian local pig breeds

An Assessment of Applicability of SNP Chip Developed for Domestic Goats in Genetic Studies of Caucasian Tur (Capra caucasica)

Caucasian tur (Capra caucasica) is native to Greater Caucasus Mountain Chain from Azerbaijan and Georgia in the East to Krasnodar region of Russia in the West. This species is divided into two subspecies (by some authors into species)—East-Caucasian tur and West-Caucasian tur and a subpopulation referred to as Mid-Caucasian tur. Up to date most of the genetic studies of Caucasian tur are based on mitochondrial DNA sequences and comprehensive investigation based on nuclear DNA is required for clarification of its genetic diversity and population structure. In our work, we assessed the applicability of Illumina Goat SNP50 BeadChip for genetic studies of Caucasian tur. Total of 15 specimens of Capra caucasica including East-Caucasian tur from Dagestan (E_TUR, n = 5), West-Caucasian tur from Karachay-Cherkessia (W_TUR, n = 5), and Mid-Caucasian tur from Kabardino-Balkaria (M_TUR, n = 5) were genotyped. After quality control, 5544 polymorphic loci, which were distributed all over 29 autosomes, were detected. The lowest number of SNPs was found on the 25th chromosome—68, and the highest on the 1st chromosome—348. It was shown that all the three groups of Caucasian tur clustered separately. A total of 2061 SNPs were common for all the populations, 594 were found only in W_TUR, 689 in E_TUR, and 530 in M_TUR. Individual heterozygosity ranged from 0.273 to 0.282 in W_TUR, from 0.217 to 0.253 in E_TUR, and from 0.255 to 0.283 in M_TUR. A clinal pattern of genetic variation was revealed. It was suggested to consider Caucasian tur a single species with several ecotypes. Thus, in our study we demonstrated that the Illumina Goat SNP50 BeadChip developed for domestic goats can be used as a useful tool for genetic studies of Caucasian tur

Comparative Study of the Genetic Diversity of Local Steppe Cattle Breeds from Russia, Kazakhstan and Kyrgyzstan by Microsatellite Analysis of Museum and Modern Samples

The comparative molecular genetic study of museum and modern representatives of cattle breeds can help to elucidate the origin and maintenance of historical genetic components in modern populations. We generated the consensus genotypes for 11 microsatellite loci for 24 museum samples of Kalmyk, Kyrgyz, and Kazakh cattle, dated from the first quarter of the 20th century, and compared them with those of modern Kalmyk, Kyrgyz, and Kazakh white-headed breeds. The level of genetic diversity of the modern Kalmyk and Kyrgyz cattle (uHe = 0.771–0.778) was similar to those observed in the museum samples (uHe = 0.772–0.776), while a visible decrease in genetic variability in the modern Kazakh white-headed breed compared to museum Kazakh cattle was detected (uHe = 0.726 and 0.767, respectively). The PCA plot, FST- and Jost’s D-based networks, and STRUCTURE clustering provided strong evidence of the maintenance of the historical genetic background in modern populations of Kalmyk and Kyrgyz cattle. In spite of the allele pool of Kazakh white-headed cattle having undergone great changes compared to the museum Kazakh cattle, several animals still carry the visible aspect of the historical genetic components. Our results can be used for the selection of individuals for the creation of gene banks and may significantly improve the efficiency of conservation programs aimed at preserving genetic diversity in the national genetic resources of cattle

Genetic Diversity of Historical and Modern Populations of Russian Cattle Breeds Revealed by Microsatellite Analysis

Analysis of ancient and historical DNA has great potential to trace the genetic diversity of local cattle populations during their centuries-long development. Forty-nine specimens representing five cattle breeds (Kholmogor, Yaroslavl, Great Russian, Novgorod, and Holland), dated from the end of the 19th century to the first half of the 20th century, were genotyped for nine polymorphic microsatellite loci. Using a multiple-tube approach, we determined the consensus genotypes of all samples/loci analysed. Amplification errors, including allelic drop-out (ADO) and false alleles (FA), occurred with an average frequency of 2.35% and 0.79%, respectively. A significant effect of allelic length on ADO rate (r2 = 0.620, p = 0.05) was shown. We did not observe significant differences in genetic diversity among historical samples and modern representatives of Kholmogor and Yaroslavl breeds. The unbiased expected heterozygosity values were 0.726&ndash;0.774 and 0.708&ndash;0.739; the allelic richness values were 2.716&ndash;2.893 and 2.661&ndash;2.758 for the historical and modern samples, respectively. Analyses of FST and Jost&rsquo;s D genetic distances, and the results of STRUCTURE clustering, showed the maintenance of a part of historical components in the modern populations of Kholmogor and Yaroslavl cattle. Our study contributes to the conservation of biodiversity in the local Russian genetic resources of cattle