Identification and molecular characterization of inducible antifungal proteins in the silkworm Bombyx mori L

Many antifungal substances found in arthropods are derived from their cuticle, which contains specialized proteins. However, certain arthropod families, particularly social insects, rely on additional antifungal substances obtained through their mutualistic relationship with microorganisms. This study focuses on the expression of antifungal proteins in silkworms after being infected with fungal pathogens, specifically infections in green and white muscardine. In the present study, the profiling of antifungal proteins which are involving in the silkworm immune mechanism was targeted. The silkworms were infected with the pathogens, and the resulting infected samples were used to extract both protein and genomic DNA. Through proteomic and genomic modelling, the expression of specific up-regulated protein was identified by using SDS-PAGE, MALDI-TOF/MS and PCR. In the samples inoculated with the pathogens, there was an up-regulation of the targeted protein (43 kDa). Proteomic analysis using SDS-PAGE and MALDI-TOF/MS confirmed the presence of the antifungal protein. The genomic study was confirmed through PCR amplification (300 and 400 bp) of the antifungal protein expression. These proteins were found to bear a resemblance to the cecropin A family protein. The results have led to the identification of an antifungal-related protein called Cecropin A. This discovery represents a significant contribution towards understanding the immune system of silkworms, as Cecropin A is one of the major proteins involved in their antifungal defense mechanisms.