is a virus resistance gene in .

INTRODUCTION

Signal peptide peptidase () is an intramembrane protease involved in a variety of biological processes, it participates in the processing of signal peptides after the release of the nascent protein to regulate the endoplasmic reticulum associated degradation (ERAD) pathway, binds misfolded membrane proteins, and aids in their clearance process. Additionally, it regulates normal immune surveillance and assists in the processing of viral proteins. Although is essential for many viral infections, its role in silkworms remains unclear. Studying its role in the silkworm, , may be helpful in breeding virus-resistant silkworms.

METHODS

First, we performed RT-qPCR to analyze the expression pattern of . Subsequently, we inhibited using the inhibitor 1,3-di-(N-carboxybenzoyl-L-leucyl-L-leucylaminopropanone ((Z-LL)-ketone) and downregulated the expression of using CRISPR/Cas9 gene editing. Furthermore, we assessed the impact of these interventions on the proliferation of nucleopolyhedrovirus (BmNPV).

RESULTS

We observed a decreased in the expression of during viral proliferation. It was found that higher concentration of the inhibitor resulted in greater inhibition of BmNPV proliferation. The down-regulation of in both in vivo and in vitro was found to affect the proliferation of BmNPV. In comparison to wild type silkworm, silkworms exhibited a 12.4% reduction in mortality rate.

DISCUSSION

Collectively, this work demonstrates that plays a negative regulatory role in silkworm resistance to BmNPV infection and is involved in virus proliferation and replication processes. This finding suggests that servers as a target gene for BmNPV virus resistance in silkworms and can be utilized in resistance breeding programs.