The Effect of Bovine Viral Diarrhoea Virus Biotypes on Bovine Oocyte In Vitro

Bovine viral diarrhoea virus (BVDV) is a significant pathogen in the global cattle population, with two biotypes: cytopathic (CP) and non-cytopathic (NCP), differing in their effects on cell culture. This study aimed to examine the impact of BVDV on the expression of apoptosis-related genes and total antioxidant capacity (TAC) in vitro. Oocytes were obtained from post-slaughter bovine ovaries and infected with both BVDV biotypes in vitro. Gene expression levels of bcl 2, bax, caspase 3 and caspase 9 were assessed using reverse transcription-quantitative PCR (RT-qPCR). The results indicated significant differences in gene expression levels, with bcl 2 expression reduced in CP and NCP-infected oocytes compared to the control group (p < 0.05). Additionally, bax and caspase 3 expression levels were significantly elevated in the CP BVDV groups (p < 0.05). In the NCP BVDV groups, the expression of bcl 2 decreased (p < 0.05), while caspase 9 expression increased by 3.588-fold compared to the control group (p < 0.05). Furthermore, TAC levels in the CP groups were significantly lower than those in the control group (p < 0.05). These findings suggest that the CP biotype of BVDV markedly affects TAC and alters the expression of key apoptosis-related genes, while the NCP biotype reduces bcl 2 expression and increases caspase 9 expression.