Identification of Core Genes of Toll-like Receptor Pathway from and Induced Expression upon Immune Stimulant.

The gypsy moth, , is a polyphagous forest pest worldwide. The baculovirus, multiple nucleopolyhedrovirus (LdMNPV) is a natural pathogen of . The Toll-like receptors (TLR) pathway plays a crucial role in both innate and adaptive immunity in animals. However, The TLR pathway and its underlying immune mechanism against baculovirus in have not been explored. In this study, eleven TLRs and five downstream TLR pathway components were identified and characterized from . Structural analysis indicated that intracellular Toll/interleukin-1 receptor (TIR) domains of LdTLRs and LdMyD88 contained three conserved motifs, and the 3D structures of TIR domains of LdTLRs possessed similar patterns in components arrangement and spatial conformation. The TLR proteins of were placed into five monophyletic groups based on the phylogenetic analysis. , , , , , and all identified downstream TLR pathway factors were highly induced upon LdMNPV infection, indicating that the TLR pathway of was activated and might play a role in the immune response to LdMNPV infection. Collectively, these results help elucidate the crucial role of the TLR pathway in the immune response of against LdMNPV, and offer a foundation for further understanding of innate immunity of the pest.