IL1B gene expression and association with SCS in Guilan native and Holstein cow populations and their reciprocal crosses
IL1B gene, as one of the interleukine-1 (IL-1) members, involves in inflammatory and immune responses, also the expression of this gene will increase due to the immune response in milk somatic cells. In the current study, the IL1B gene expression was compared among four different genotypes including native and purebred cows and their crosses. Real-time PCR technique was used to evaluate the expression of the IL1B target gene by applying two internal control genes (GAPDH and RPLP0). The highest and lowest IL1B gene expression was obtained in Guilan native and Holstein-sired crossbred cows, respectively. Statistical analysis revealed that there are significant expression differences of IL1B gene amongst studied populations (p<0.05). The highest (14.18) and lowest (13.27) SCS was observed in the Guilan native-sired crossbred cows and Guilan native cows, respectively. A significant negative correlation (-0.34) was obtained for IL1B gene expression and SCS of studied populations (p < 0.05). A negative correlation between IL1B gene expression and SCS may show the importance of higher expression of IL1B gene in immune responses related to cow udder infection. The higher fold-change ratio of IL1B gene in the robust native cows to the other studied groups showed that the importance of this gene in resistance and tolerance.