New insights into the prolactin-RsaI (PRL-RsaI) locus in Chinese Holstein cows and its effect on milk performance traits

Abstract

ABSTRACT. Prolactin (PRL) plays central roles in mammals' reproduction, gland development, milk secretion, and the expression of milk protein genes. In dairy cattle, the PRL gene is a potential quantitative trait locus and genetic marker related to milk performance traits. Here, a total of 586 randomly selected Chinese Holstein cows were genotyped for locus PRL-RsaI. One haplotype block containing eight SNPs was identified in the region from intron 3 to intron 4 of the PRL gene in Chinese Holstein cows. One tag SNP (7545 G→A) was selected to represent the haplotype block defined by the genotypic data. The cows with genotype AA of this tag SNP had a higher milk yield at 305 days (8457 ± 938 kg) than the cows with GA (7537 ± 1278 kg; P < 0.01) or GG (7757 ± 1174 kg; P < 0.05). This suggests that the haplotype block examined in this study contains important markers for milk production traits in Chinese Holstein cows.

Assessment of Genetic Variability in Prolactin Gene and Its Impact on Milk Composition in Bos indicus Cattle

“…The candidate gene approach (El-Magd et al, 2014) have detected bovine prolactin (bPRL) gene as one of the potential candidate gene that have significant impact on milk composition traits in dairy cattle (Komisarek and Dorynek, 2009) due to their positional role on chromosome 23 at 43 cM, close to the quantitative trait loci region (QTLs) of 36, 41, and 42 cM (Bennewitz et al, 2004). The prolactin gene invariably affects growth and development of mammary gland (mammogenesis), synthesis of milk (lactogenesis) and maintenance of milk secretion (galactopoiesis) (Dong et al, 2013). The indirect effect of prolactin gene on milk production traits occurs through its modulatory role on thermoregulatory mechanisms during hot climates (Alamar, 2011) and regulatory role in calcium homeostasis through enhanced intestinal calcium absorption (Charoenphandhu and Krishnamra, 2007).…”

Genetic variability of myostatin and prolactin genes in popular goat breeds in Egypt

“…Many researchers recorded that PRL polymorphisms are related to wool or cashmere traits in goat and sheep [12], [13], [14] . Others studied the association polymorphism of PRL with dairy traits like benefit yield besides the yield of protein milk in cattle breeds [15], [16], [17] . Furthermore, many researcher suggested the significance of PRL gene in improving prolificacy in different sheep breeds [18], [19].…”

Reproductive efficiency and serum progesterone concentration on dairy cattle based on blood urea nitrogen (BUN) concentrations

“…AA, AG, and GG. Cattle with AA genotype have higher milk yields than cows with GA or GG genotype (24). The genotypes AA, AG, and GG have the frequency of 0.07, 0.34, and 0.59, respectively, in the livestock population (25).…”