Research on How Host circRNA Affects the Replication Differences Between Strong and Weak Strains of PRV FA and FB

Pseudorabies virus (PRV) is the pathogen that causes pseudorabies in pigs. Clinical symptoms in pig herds include neurological symptoms in piglets, respiratory symptoms in medium to large pigs, and reproductive disorders in sows. PRV replication is related to the regulation of virus virulence and is also regulated by host factors. Therefore, in addition to studying the impact of genetic variations in the virus genome on virus replication, identifying host factors that affect the replication of porcine pseudorabies virus and studying the molecular mechanisms by which host factors affect virus replication are of great significance for understanding the replication differences between strong and weak strains of PRV.Circular RNA (circRNA) is a type of endogenous non coding RNA that widely exists in organisms in a closed circular form. It plays an important role in viral infection, regulation of gene expression, and host antiviral immune response, and is closely related to the occurrence of diseases. Previous studies have reported differences in circRNA expression profiles between PRVDX parental strains and deletion strains (DXgETK -), and found that the deletion of virulence genes leads to differences in circRNA expression, thereby affecting PRV replication. Our previous research found that the PRV attenuated strain FB (FA strain bred into a attenuated strain after 680 generations) and its parent virulent strain FA did not undergo deletion or mutation at the level of major virulence and immune genes, but the replication of FA and FB on cells showed differences. Therefore, the mechanism of differential replication between strong and weak PRV strains in FA and FB may be inconsistent with previous reports, and it is worth exploring and studying whether it regulates virus replication through differential host circRNA expression.To this end, this project analyzed the differential expression profiles of circRNA in BHK-21 cells infected with strong and weak PRV strains FA and FB, predicted and constructed a circRNA miRNA mRNA associated ceRNA network using bioinformatics software, and identified circRNAs related to replication; By using siRNA interference and overexpression techniques, the effect of circRNA on the replication of strong and weak strains of PRV was validated on cells, thus preliminarily elucidating the molecular mechanism of host circRNA regulation of the replication differences between strong and weak strains of PRV. Therefore, the research significance of this project is to explore the host factors that affect the replication differences between strong and weak strains of PRV by studying the circRNA differential expression profiles of FA and FB, and to provide theoretical basis for studying the infection and antiviral mechanisms of strong and weak strains of PRV from the host perspective.