Viperin (RSAD2) gene expression in peripheral blood mononuclear cells of pregnant crossbred beef cows is altered by Bos indicus genetics

Abstract

The expression of interferon (IFN) stimulated genes (ISGs) in lymphocytes has been used for pregnancy diagnosis in cattle. However, among-cow variability has yielded sub-optimal predictive accuracy. We hypothesized that the expression of ISGs (ISG15, OAS1, RSAD2, CLEC3B, and AKR1B1) in early pregnancy varies according to the proportion of Bos indicus (B. indicus) genetics on females. Multiparous cows were classified in three genetic groups, High Angus (HA; n = 45 [0–33% Brahman influence]), Angus-Brahman (AB; n = 30 [34–67%]), and High Brahman (HB; n = 19 [68–100%]) and submitted to a Select-Synch + CIDR protocol. Cows that displayed estrus (n = 94) were artificially inseminated (Day0; D0). On D19, blood samples were collected to obtain peripheral blood mononuclear cells (PBMC) and measure progesterone (P4) concentrations. On D30, pregnancy diagnosis was performed. The expression of RSAD2 in PBMC of pregnant cows was positively related to the proportion of B. indicus genetics of the groups, but not the expression of ISG15 and OAS1. In pregnant cows, the proportion of B. indicus genetics was negatively associated to circulating levels of P4 concentrations. The P4 concentrations were related positively with RSAD2 expression. ROC curve results determined that for cattle with B. indicus genetics lower than 67%, the CLEC3B and AKR1B1 combination was the most accurate option to predict the outcome of pregnancy. In cows with more than 68% of B. indicus genetics, RSAD2 provided the best accuracy. In conclusion, there is a relationship between the proportion of B. indicus genetics and the ISGs gene expression in PBMC during pregnancy.