The aim of the present study was to describe the genetic polymorphism of the -LG milk protein locus in the Lithuanian Blackface sheep breed obtained using isoelectric focusing (IEF) method and in the Lithuanian Native Coarse wool sheep – using PCR-RFLP method. The results of study as follows: in Lithuanian Blackface sheep two genetic variants A and B with allele frequency of A=0.52 and B=0.48 were identified. The most frequent genotype in Lithuanian Blackface breed, detected in 66.7 % of studied individuals, was heterozygous genotype AB. Homozygous genotypes AA and BB were observed at frequencies of 19.0 % and 14.3 %, respectively. In Lithuanian Native Coarse wool sheep two genetic variants A and B with allele frequency of A=0.69 and B=0.31 were identified. The BB genotype was not frequent (7.8 %) in Lithuanian Native Coarse wool breed. The genotypes AA and AB were observed at frequency of 46.1 %. Mean observed heterozygosity value (Hobs=0.511) in Lithuanian Blackface sheep was slightly lower than mean expected heterozygosity (Hexp=0.667). In Lithuanian Native Coarse wool sheep mean expected heterozygosity value (Hobs=0.461) was similar to the mean observed heterozygosity (Hexp=0.434). The deviation from Hardy-Weinberg equilibrium was not detected in any of those breeds. Conclusions: the detected high frequency of genotype AB in meat-wool type Lithuanian Blackface and Lithuanian Native Coarse wool sheep might be in agreement with the observations made by Bocharev. Since the... [to full text]