Transcriptomic Analysis of Mulberry (Morus spp.) Leaves and Its Impact on Gene Expression in Silkworm (Bombyx mori) for Enhanced Silk Production

Abstract

Mulberry (Morus spp.) leaves serve as the exclusive food source for the silkworm (Bombyx mori), directly influencing its growth, development, and silk production. This study investigates the gene expression profiles associated with mulberry leaf quality and their subsequent impact on silkworm performance using transcriptomic approaches. High-quality and low-quality mulberry leaves were identified based on biochemical parameters and subjected to RNA sequencing (RNA-Seq) analysis to identify differentially expressed genes (DEGs). Simultaneously, silkworm larvae fed on these leaves were analyzed to determine gene expression changes related to growth and silk protein synthesis. The results revealed significant upregulation of genes associated with photosynthesis, nitrogen metabolism, and secondary metabolite biosynthesis in high-quality mulberry leaves. In silkworms, genes related to fibroin and sericin synthesis, including Fib-H, Fib-L, and Ser1, were significantly upregulated when fed with high-quality leaves. Pathway enrichment analysis indicated enhanced amino acid metabolism and protein biosynthesis in these larvae. Conversely, silkworms fed with low-quality leaves exhibited increased expression of stress-related genes. This study establishes a molecular link between mulberry leaf quality and silkworm silk production, providing insights into gene-level interactions. The findings highlight the potential of integrating transcriptomics in sericulture to improve silk yield and quality through targeted crop and feeding strategies.