Variability of microsatellites in sheep breeds raced in Russia

At the current stage of biological development is impossible to establish conservation programs and to monitor genetic resources of sheep without a preliminary study by DNA markers. The Russian sheep breeding is represented by wide variety of breeds, including all productivity and wool types. However, until recently only some sheep breeds, which belong to the same breeding zone or productivity type, were investigated by DNA markers including microsatellites. We studied 25 Russian sheep breeds ( n = 751), including fine-fleeced - Dagestan Mountain (DAG), Grozny (GRZ), Kulunda (KUL), Manych Merino (MNM), Salskaya (SAL), Stavropol (STA), Soviet Merino (SVM), Volgograd (VOL), Baikal’s fine-fleeced (ZBL); semi fine-fleeced - Altay Mountain (ALT), Kuibyshev (KUI), North Caucasian (NC), Russian long-haired (RLH), Tsigai (TSIG); coarse-wooled - Andean (AND), Buubey (BUB), Edilbai (EDL), Karachaev (KAR), Kuchugur (KCH), Kalmyk (KLM), Karakul (KRK), Lezgin (LEZ), Romanov (ROM), Tushin (TSH), Tuvan short fat-tailed (TUV). The research was conducted using 11 microsatellite loci (OarCP49, INRA063, HSC, OarAE129, MAF214, OarFCB11, INRA005, SPS113, INRA23, MAF65 и McM527). The data were processed using GenAIEx 6.5 and PAST software. In general, the studied breeds were characterized by moderately high allelic diversity. The average number of alleles per locus is varied from 7.20±0.98 in KUL and 10.30±0.99 in TSIG. The values of Na≥10.0 were found in TSIG, TUV, BUB and KRK, values of Na≤8.0 were identified in KUL, RLH and SVM. The effective allele number was the highest in the KRK and TUV (Ne≥5.7) and the minimum was detected in KCH, ALT, RLH and NC (Ne≤4.3). The level of the observed heterozygosity in 21 of the 25 studied breeds ranged from 0.489±0.095 in TUV to 0.651±0.050 in ROM and 0.651±0.060 in SVM, and four other breeds (BUB, TSIG, ZBL and TUV) it varied from 0.798±0.023 in BUB up 0.977±0.017 in TUV. There was a substantial deficit of heterozygotes in 21 of the 25 studied breeds (FIS values ranged from 0.13 in ROM to 0.36 in KAR and SAL), in the other four (BUB, TSIG, ZBL and TUV) an excess of heterozygotes (FIS values ranged from -0.04 to -0.22) was detected. The analysis of molecular variance (AMOVA) showed that 5.02 % of genetic variation is composed of differences among breeds and 94.98 % is explained by within breeds’ component. Analysis of the structure of the UMPGA phylogenetic tree, based on the matrix of pairwise genetic distances by M. Nei (1972), showed that the nature of the identified relationships is mainly related with the wool type, productivity type and breeding region. Thus, the identified polymorphism of eleven microsatellite loci is quite powerful for differentiating sheep of various breeds. For a better understanding population structure and obtaining new information on the genetic diversity at the genomic level the application of DNA microarrays, based on the multiple SNPs-markers, is required.