Ewa Pecka-Kiełb1, Ewa Czerniawska-Piątkowska2, Inga Kowalewska-Łuczak2, Milan Vasil3. 1. Department of Biostructure and Animal Physiology, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland. 2. Department of Genetics and Animal Breeding, West Pomeranian University of Technology, Szczecin, Poland. 3. Department of Epizootology and Parasitology, University of Veterinary Medicine and Pharmacy, Košice, Slovak Republic.
Abstract
BACKGROUND: Annexin A9 (ANXA9) is a specific fatty acid transport protein. The ANXA9 gene is expressed in various tissues, including secretory tissue and the mammary glands. The association between the three single nucleotide polymorphisms (SNPs) of the ANXA9 gene and sheep's milk composition was assessed. RESULTS: Genotype analysis was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The ANXA9 polymorphisms that were studied had the following major allele frequencies (MAFs): SNP1: allele G 0,66; SNP2: allele G 0,54; SNP3: allele C 0,57. The study found the most favorable profile of protein fractions, namely increased kappa-casein fractions and a decreased level of whey protein in sheep's milk for the SNP1 and SNP3 polymorphisms. Sheep with the SNP1 GA genotype had the highest (P < 0.05) content of fat and dry matter in milk. AXNA9 gene polymorphism did not influence the levels of protein, lactose, or urea in sheep's milk. CONCLUSION: The information contained in this study may be useful for determining the impact of the ANXA9 gene on sheep's milk. The ANXA9 SNP1 and SNP3 polymorphism results could be included in breeding programs to select sheep with the genotypes ensuring the highest kappa-casein levels in milk. However, it is worth conducting further research on ANXA9 and milk composition in larger herds of animals and various breeds of sheep.
BACKGROUND:Annexin A9 (ANXA9) is a specific fatty acid transport protein. The ANXA9 gene is expressed in various tissues, including secretory tissue and the mammary glands. The association between the three single nucleotide polymorphisms (SNPs) of the ANXA9 gene and sheep's milk composition was assessed. RESULTS: Genotype analysis was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The ANXA9 polymorphisms that were studied had the following major allele frequencies (MAFs): SNP1: allele G 0,66; SNP2: allele G 0,54; SNP3: allele C 0,57. The study found the most favorable profile of protein fractions, namely increased kappa-casein fractions and a decreased level of whey protein in sheep's milk for the SNP1 and SNP3 polymorphisms. Sheep with the SNP1 GA genotype had the highest (P < 0.05) content of fat and dry matter in milk. AXNA9 gene polymorphism did not influence the levels of protein, lactose, or urea in sheep's milk. CONCLUSION: The information contained in this study may be useful for determining the impact of the ANXA9 gene on sheep's milk. The ANXA9 SNP1 and SNP3 polymorphism results could be included in breeding programs to select sheep with the genotypes ensuring the highest kappa-casein levels in milk. However, it is worth conducting further research on ANXA9 and milk composition in larger herds of animals and various breeds of sheep.