Polymorphisms in JAK2 Gene are Associated with Production Traits and Mastitis Resistance in Dairy Cattle

Abstract

The present study was designed to investigate the effects of single nucleotide polymorphisms (SNPs) in the JAK2 gene on the production and mastitis related traits in dairy cattle. Blood and milk samples were collected from 201 lactating dairy cattle of three breeds, i.e. Holstein Friesian (HF), Jersey (J) and Achai (A) and their crosses maintained at well-established dairy farms in Khyber Pakhtunkhwa, Pakistan. Generalized linear model was used to evaluate the association between genotypes and the studied traits. A DNA pool was made from randomly selected 30 samples which revealed three SNPs, i.e. SNP 1 in 5’ upstream region (G>A, rs379754157), SNP 2 in intron 15 (A>G, rs134192265), and SNP 3 in exon 20 (A>G, rs110298451) that were further validated in the population under study using SNaPshot technique. Of the three SNPs, SNP 1 did not obey Hardy-Weinberg equilibrium (P<0.05). SNP 2 and SNP 3 were found to be in strong linkage disequilibrium and allele G was highly prevalent compared to allele A in these SNPs. in SNP 1, the GG genotype was associated with significantly (P<0.01) higher SCC, whereas SNP 2 and SNP 3 were significantly (P<0.01) associated with higher lactose percentage compared to the other geno-types. The haplogroups association analysis revealed that H1H2 (GG GG AG) has significantly lower SCC than H2H2 (GG GG GG). The results infer that JAK2 could be an important candidate gene and the studied SNPs might be useful genetic markers for production and mastitis related traits.

Association of Aberrant DNA Methylation Level in the CD4 and JAK-STAT-Pathway-Related Genes with Mastitis Indicator Traits in Chinese Holstein Dairy Cattle

“…Large numbers of pathogens causing mastitis; therefore, successful vaccination to control the disease is not effective. Generally, antimicrobial agents and management strategies are used to combat the disease in dairy cattle [ 5 ]. However, marker-assisted selection using genetics and epigenetics approaches is considered an appropriate strategy to minimize the incidence of mastitis in dairy cattle [ 6 , 7 ].…”

Identification of single nucleotide polymorphism within bactencin-5 and bactencin-7 coding genes in association with milk production traits

“…Relationships between somatic cell counts and polymorphisms within cattle genes have been analyzed extensively, and there is a constant need to improve knowledge to improve health in dairy cows, which translates into lower production losses. The association between polymorphisms within genes encoding defensins -also be-longing to AMPs -concerning milk production parameters was studied by Brodowska et al [2019], and the study yielded results that can support appropriate animal selection for best performance, as well as an analysis by Ali et al [2020] showed that another gene, Jak2, can be an essential candidate gene, and SNPs studied within it can be helpful to genetic markers for traits related to production and mastitis. Research by Rasheed et al [2020] showed an association between SNPs located in the CD4 gene promoter gene and dairy cattle production traits and mastitis indicators.…”

Role of the JAK-STAT Pathway in Bovine Mastitis and Milk Production

“…It has been consistently reported that the polymorphisms T-C39652459 and T-C39645396, at intron 15 and exon 20, respectively, in the JAK2 gene, are significantly associated with milk lactose production in dairy cows [ 49 ]. Furthermore, the variant JAK2 / RsaI is involved in the regulation of milk and milk protein and can be considered a milk production marker in dairy cattle [ 50 ].…”