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

## TL;DR

This study shows how two types of BVDV virus affect gene activity and antioxidant levels in cow egg cells in the lab.

## Contribution

The study reveals distinct impacts of cytopathic and non-cytopathic BVDV biotypes on apoptosis-related gene expression and antioxidant capacity in bovine oocytes.

## Key findings

- CP BVDV significantly reduces bcl 2 expression and increases bax and caspase 3 expression in bovine oocytes.
- NCP BVDV decreases bcl 2 expression and increases caspase 9 expression compared to the control group.
- CP BVDV leads to significantly lower total antioxidant capacity (TAC) in oocytes than the control group.

## Abstract

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.

Bovine viral diarrhoea virus (BVDV) is a significant pathogen with two biotypes, cytopathic (CP) and non‐cytopathic (NCP). The aims were to examine the impact of BVDV on the expression of genes related to apoptosis and total antioxidant capacity (TAC) in vitro. Oocytes were infected with two BVDV biotypes. For assessing the bcl 2, bax, caspase 3 and caspase 9 gene expression, RT‐qPCR was used. The results showed significant differences in gene expression levels, including bcl 2, bax, caspase 3 and caspase 9, in the CP BVDV groups compared to the control group. Only bcl 2 and caspase 9 expression levels significantly decreased in the NCP BVDV groups compared to the control group. In addition, the CP groups TAC levels were much lower than those of the control group. It can be inferred that CP BVDV has a notable impact on the TAC of oocytes and alters the expression of genes such as bcl 2, bax, caspase 3 and caspase 9. However, the NCP biotype only leads to a decrease in expression of bcl 2 and caspase 9.