Analysis of genetic structure in Polish Red and Polish Black-and-White cattle using twelve marker loci potentially related to milk or meat production traits*

Polish Red (PR) is the native Polish cattle breed included in the FAO National Rare Livestock Breeds Preservation Programme. The breed is characterized by high vitality and fertility, calving ease, resistance to diseases, and low requirements for feed. Milk yield is low, but fat and protein content of milk are high. The frequencies of alleles of commonly studied loci as well as the presence of new or rarely reported DNA polymorphisms were studied in a group of about 300 PR cows belonging to two subpopulations. Moreover, gene frequencies were compared between two PR subpopulations, and with a reference population of the Black-and-White (BW) cattle. The investigation was intended to reveal the genetic specificity of PR and provide new arguments for its protection. Except for loci Pit1 and GH-MspI, the allele frequencies of CSN3, LGB, GH-AluI, GHRH, LEP and PRL genes in PR were found different from those appearing in BW cattle. Although the estimated genetic distance between PR and BW populations appeared very short (0.0146, R=0.986), variants of several genes identified in PR were found absent or very rare in BW cattle. These included the LGBI variant, 11-bp deletion in MSTN gene, as well as several unique nucleotide sequence variants of 5’noncoding regions of CSN1S1, CSN1S2, GH, and PRL genes. At loci CSN3, LGB, IGF1 and GH-AluI significant differences were found also between the two PR subpopulations studied.