β-fructofuranosidase regulation in silkworm silk gland development: Implications for silk gland morphogenesis and silk production.

This study investigates the impact of β-fructofuranosidase (Bmsuc1) on the development of the silk gland in silkworms (Bombyx mori). Previous research shows that Bmsuc1 is highly expressed in the silk glands and may be involved in silk gland development and protein synthesis. However, the precise mechanism by which Bmsuc1 regulates silk gland development remains unclear. This study specifically used RNA interference to inhibit Bmsuc1 expression in silkworm larvae. The results revealed that silencing Bmsuc1 led to significant shortening of the anterior silk gland cells, left and right side size asymmetrical development of the middle silk gland, and alterations in cellular and inner membrane layer thickness. Furthermore, the glucose and fructose levels in the silk gland were significantly reduced, reducing cocoon weight. The interference of Bmsuc1 also triggers carbohydrate metabolism-related genes, beta-hexosaminidase subunit (HEXA-β) and glucose-6-phosphatase (G6Pase), which were upregulated. In addition, cell cycle-related genes, Cyclin E and cyclin-dependent kinase 2 (CDK2), were downregulated. These findings provide a new theoretical foundation for understanding the molecular mechanisms of silk gland development and offer insights into improving silk yield.