The Significance of a Multilocus Analysis for Assessing the Biodiversity of the Romanov Sheep Breed in a Comparative Aspect

SIMPLE SUMMARY: The history of the Romanov breed goes back more than a century, with the first mention being made in 1802. This breed has unique qualities, such as a good resistance to harsh environments, high litter size, polyestrousity, early maturation and excellent fur coat qualities. In this work, we highlighted several genetic markers involved in these characteristics. The high ovulation rate of the Romanov breed is probably linked to the polymorphism recorded in two genes located on different chromosomes. The breed’s adaptation to the harsh environment of its breeding area in the Russian Federation could be associated to a high level of heterozygosity. In addition, the dilemma of its obscure origin was also addressed by comparison with other Russian breeds of different productive orientations. ABSTRACT: The Romanov breed was evaluated using immunological and genetic markers. The seven blood group systems were characterized with a greater accuracy than in previous works on sheep in the Russian Federation, and were compared to eight ruminant species. Unlike other breeds, Romanov sheep shows a higher frequency of HB(A) than HB(B) alleles. There are 3–4 genotypes at the transferrin locus whereas in other breeds 6–11 genotypes have been found. At the albumin locus, the majority of the identified genotypes were heterozygotes, unlike in the other breeds studied. In the prealbumin locus, the Romanov breed was the only one where all the genotypes were heterozygous. We speculate that polymorphism at two loci (BMP-15 and BMPR1B) could effect on the high ovulation rates of Romanov sheep. Based on different genetic markers, the prevalence of heterozygotes in the Romanov sheep could determine their higher viability. A cluster analysis showed the close proximity of 12 populations of the Romanov breed, as the breeding stock come from the Yaroslavl region.