The Polymorphism in Various Milk Protein Genes in Polish Holstein-Friesian Dairy Cattle

Abstract

The aim of the present study was to evaluate the genotype and allele frequencies of 24 polymorphisms in casein alpha S1 (CSN1S1), casein alpha S2 (CSN1S2), beta-casein (CSN2), kappa-casein (CSN3), and progestagen-associated endometrial protein (PAEP) genes. The study included 1900 Polish Black and White Holstein-Friesian dairy cows that were subjected to genotyping via microarrays. A total of 24 SNPs (Single Nucleotide Polymorphisms) within tested genes were investigated. Two CSN1S1 SNPs were monomorphic, while allele CSN1S1_3*G in CSN1S1_3 SNP dominated with a frequency of 99.39%. Out of seven CSN2 SNPs, four were polymorphic; however, only for CSN2_3 all three genotypes were detected. Only three out of nine SNPs within CSN3 were monomorphic. Three PAEP SNPs were also found to be polymorphic with heterozygotes being most frequent. Hardy–Weinberg equilibrium (HWE) was observed for eight variants. It was shown that only CSN3_6 was not in HWE. The fact that many of investigated SNPs were monomorphic may suggest that in the past the reproduction program favored one of these genotypes. SNPs that are included in commercially available microarrays should be monitored in relation to changes in their frequencies. If a SNP has turned monomorphic, maybe it should be considered for removal from the microarray.

Evaluación de la calidad composicional, sanitaria y microbiológica de la leche en el municipio de Sapuyes, departamento de Nariño, en el año 2021

“…Asimismo, hay otros parámetros que cambian la composición de la leche, entre estos se encuentra la alimentación, que es un factor que altera de manera más evidente la producción de grasa, lo que ha permitido mejorar su valor con el manejo nutricional. Por otra parte, la proteína de la leche tiene un elevado componente genético, lo que dificulta su mejora con actividades de manejo, por lo que se recurre al mejoramiento genético para lograr incrementos 11 .…”

Genotyping, physicochemical characterization, and protein isoform quantification of β-casein A2 milk in chinese simmental and Angus cattle

“…Technical efforts to increase milk safety, quality, and chemical composition by implementing standard animal breeding practices, controlling environmental factors, and selecting favorable haplotypes are significant in the modern dairy industry (Brito et al, 2021;Caroli et al, 2009;Marchitelli et al, 2013). In ruminant milk, casein accounts for nearly 80% of its total protein and is physiochemically encoded by four casein haplotype genes, which are α-S1-CN (CSN1S1), α-S2-CN (CSN1S2), β-CN (CSN2), and κ-CN (CSN3), located in a 250-kb spanning region on bovine chromosome 6 (Caroli et al, 2009;Kolenda et al, 2021;Vanvanhossou et al, 2021). Among those haplotypes, the CSN2 gene plays an essential role in the determination of the surface properties of the casein micelles, influences milk yield, physicochemical properties, quality, composition, processability, and nutrition balance in dairy products (Cieślińska et al, 2019;Dai et al, 2016;Gai et al, 2021;St-gelais and Haché, 2005).…”

Effect of Protein Genotypes on Physicochemical Properties and Protein Functionality of Bovine Milk: A Review

“…As the demand for milk and milk products increases continuously, and since milk provides essential nutrients in the human diet [1,2], studies on milk and dairy products have generated a lot of attention in dairy related research.…”

“…Protein is a macronutrient for the human body [1], and accounts for about 3.5% of milk mass, typically comprising approximately 80% casein and 20% whey protein [2]. Four forms of casein are found in milk protein, including α S1 -CN, α S2 -CN, β-CN, and κ-CN, and their genes are found at bovine chromosome 6 [3,4], coded as CSN1S1, CSN1S2, CSN2 and CSN3, respectively [1,5]. These proteins have several genetic variants, as described by Caroli et al [6] and Farrell et al [7].…”

“…These proteins have several genetic variants, as described by Caroli et al [6] and Farrell et al [7]. The gene of α-lactalbumin (α-lac) in the whey protein fraction is located on bovine chromosome 5, coded as LAA [3], and that of β-lactoglobulin (β-lg) is coded by the PAEP gene (or LBG gene) [1], which is situated on bovine chromosome 11 [8]. Polymorphisms of CSN1S1, CSN2, CSN3 and PAEP have widely been studied [6,9], but only a few polymorphs of LAA and CSN1S2 have been identified, mainly in French breeds [10].…”