Genetic Association of Polymorphism and Relative mRNA Expression of Tumor Necrosis Factor-Alpha Gene in Mastitis in Sahiwal Cow

Bovine mastitis is a host response to the microorganisms linked with the host immune system efficiency. Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine that plays a significant role in the innate and adaptive immune response. In this study, we characterized the upstream regulatory region and evaluated the relative mRNA expression of TNF-α gene of Sahiwal cows. A single nucleotide polymorphism A>G was identified located within a sequence (MT_919286) at the 5´ upstream region. For gene expression, the ΔΔCt was calculated by adjusting the target gene expression for the expression of the housekeeping gene (GAPDH) through real-time qPCR. The results revealed that relative mRNA expression of TNF-α most explains the change in the unit of ΔCt and would result in a significantly higher expression of TNF-α gene in animals with mastitis. The relative mRNA expression of TNF-α gene was 35 and 9.53 times higher in animals with clinical and subclinical mastitis respectively, as compared to non-mastitic animals. The effect of the fold change of TNF-α and GAPDH was also assessed based on response surface methodology via Box Behnken design. The analysis depicted that all parameters had a significant impact on mastitis incidence in Sahiwal cows. This study would hopefully contribute towards a better understanding of the use of TNF-α gene marker as an authentic source of identification of severity of bovine mastitis. The findings of study may be helpful for the development of new strategies to control mastitis and preserve the health of dairy animals. © 2021 Friends Science Publishers