Zootechnicheskii, Stavropol, 355017 Russia; 3Institut fьr Tierzucht und Genetik, University of Veterinary Medicine (VMU), Veterinдrplatz, A-1210, Vienna, Austria, e-mail gottfried.brem@agrobiogen.de Acknowledgements: We thank Dr R.V. Ivanov (Yakut Research Institute of Agriculture) for assistance in collecting samples Supported by Russian Science Foundation (project ¹ 14-36-00039) Received September 26, 2016 A b s t r a c t 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); coarsewooled — 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 data were processed using GenAIEx 6.5 and PAST software. <...> In general, the studied breeds were characterized by moderately high allelic diversity. <...> 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). <...> 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 <...>