Identification of genetic marker for prolactin gene related to milk yield in pedigreed Sahiwal population

Abstract

The study was conducted to identify the genetic marker for prolactin gene related to milk yield in pedigreed Sahiwal population. PCR-RFLP was carried out by using Rsa1 restriction endonuclease and revealed three genotypes GG, GA and AA in Sahiwal population. The frequency of G and A allele of Prolactin gene (exon 3) was estimated as 0.575 and 0.425, whereas the frequencies of GG, GA and AA genotypes for Prolactin gene (exon 3) were estimated as 0.45, 0.25 and 0.30, respectively. Regression analysis inferred that, SNP (G55A) of prolactin gene (exon 3) contributed to an increase in the average test day milk yield by 321.5g which was 3.92% of the average test day milk yield. Forty Sahiwal animals (20 families) under Daughter- Dam Design were screened and it was observed that one SNP (G55A) was found in all the nine families (45%) having heterozygous (GA) genotype. Thus, it could be considered as a potential genetic marker for high milk production in Sahiwal population.

Detecting the Molecular Associations of Prolactin Gene Genotypes With Milk Traits in Friesian and Baladi Cows Using RFLP Technique

“…Kumari et al (2008) in India reported frequencies of AA, BB and AB genotypes to be 0.22, 0.13 and 0.65 in Jersey cattle with allelic frequencies of 0.55 for A allele and 0.45 for B allele. Karuthadurai et al (2019) reported also in India that the frequencies of AA, GG and GA genotypes of Sahiwal cattle were 0.30, 0.45 and 0.25, respectively with allelic frequencies of 0.425 for A allele and 0.575 for G allele. In Croatia, Mauriae et al (2017) stated that most of the animals of Simmental and crossbred Holstein cattle were genotyped as GG homozygous genotype for PRL gene.…”

“…However, the polymorphism in exon 3 and 4 of the prolactin gene in dairy cattle was clarified and protocoled by several investigators (e.g. Zhang et al, 2008;Hu et al, 2009;Mehmannavaz et al, 2009;Das et al, 2012;Karuthadurai et al, 2019;Bayıl and Bozkurt, 2019;Dudule et al, 2020;Shah et al, 2021, andSamuel et al, 2023).…”

“…Mehmannavaz et al (2009) detected a mutation in 294-bp fragment of PRL gene located in exon 4 in Iranian Holstein cattleusing PCR-RFLP technique and RsaI restriction enzyme. Karuthadurai et al (2019) in Sahiwal cattle found that the fragments of genotype GA had 156, 84 and 72 bps, the genotype GG had 84 and 72 bps and the genotype AA had 156 bp.…”