Molecular characterization of IGF-1 gene expression in crossbred calves exposed to acute heat stress in a climate-controlled environment

Abstract

Heat stress in livestock causes tremendous impacts on their overall production, productivity and health. Cattle are homeotherms, initiate various thermo-regulatory mechanisms to maintain homeostasis. Molecular adaptations are considered as dominant mechanism in thermoregulation. There are changes in the expression patterns of certain genes that are fundamental for thermo-tolerance at the cellular level in cattle. The present study was conducted exclusively to characterize the Insulin-like Growth Factor-1 (IGF-1) gene expression in heat-stressed calves under controlled climatic conditions using thermo-neutral zone as control. Venous blood samples with anti-coagulant were collected for gene expression studies in the peripheral blood leukocytes of calves in both the groups by quantitative real-time polymerase chain reaction (qRT-PCR) using GAPDH as housekeeping gene. The present study shown that the IGF-1 gene expression shown a non-significant down regulation under heat stress when compared to thermo-neutral zone. It was clear from the findings that crossbred calves were trying to maintain thermal homeostasis by employing molecular adaptations when they were exposed to controlled environmental challenges and gave a focus on energy conservation for broader shift of gene expression towards thermo-regulation.