Всероссийский научно-исследовательский институт физиологии, биохимии и питания животных – филиал Федерального государственного бюджетного научного учреждения «Федеральный научный центр животноводства – ВИЖ имени академика Л.К. Эрнста»
ABSTRACT. The aim was to study genetic structure of Romanov sheep populations in four regions of Russian Federation using three type of marker systems (blood groups, polymorphic blood proteins, microsatellites), to access genes fluxes between regions, and characterize the relationship between BMP-15 locus and reproductive function of ewes. Predominance of heterozygotes is found in five blood group systems; homozygotes prevail only in R and D. In Romanov breed sheep, superiority of HBA allele frequency seems to prevail over HBB allele frequency, and the heterozygous genotype with HBAB prevails over the genotype with HBAA and HBBB homozygotes. Such a form of a hemoglobin locus was not identified in Russian and most of foreign breeds. Three to four genotypes were revealed in Romanov breed sheep with the transferrin locus. Heterozygote superiority and absence of rare genotypes are typical for it. The similar pattern is observed at albumin and prealbumin loci; the heterozygous genotypes also prevail there. In the Romanov sheep breed, the right side excess at polymorphic loci seems to prevail which is evidence to overabundance of heterozygotes. Hemoglobin locus with the left side excess was indicated in populations from Yaroslavl and Voronezh oblast. The obtained level of genetic distance varied from 0.59 to 1.16. The level of homozygosity (Ca) averages 0.5 by seven blood group systems, 0.4 and 0.3 at polymorphic loci and microsatellites respectively. The relationship was revealed between genotypes by BMP-15 locus and multiple pregnancy as well as between barrenness and culling rate in Romanov breed. The highest number of lambs was indicated in homozygous (MM) for the mutant allele and in heterozygous females (WM). The largest percentage of culling rate and barrenness was detected in WW ewes. So, in selection of females on fertility, genotypes have to be considered on the locus of BMP-15, although the birth of two or more lambs in animals with genotype WW indicates the existence of yet unknown biological mechanism, which also has an impact on fertility and requires further research.
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