Soluble Guanylate Cyclase α1 Gene Influences Egg-Laying Amount and Hatching Rate in Bombyx mori

Soluble guanylate cyclase (sGC) serves as a receptor of nitric oxide (NO) and is the core metalloenzyme in the NO signal transduction pathway. sGC plays a key role in the NO-cGMP signal transduction pathway and participates in various physiological processes, including cell differentiation, neuron transmission, and internal environment homeostasis. sGC consists of two subunits, α and β, each subunit containing multiple isoforms. In this study, we cloned and analyzed the sGC-α1 gene in the silkworm Bombyx mori (BmsGC-α1). The BmsGC-α1 gene was expressed highest at the pupal stages. The highest BmsGC-α1 mRNA expression was observed in the head of fifth instar larvae and in fat body during the wandering stage of B. mori. Furthermore, we observed that feeding fifth instar larvae with thyroid hormone and nitroglycerin induced the expression of the BmsGC-α1 gene. Injection of BmsGC-α1 siRNA into silkworms at the prepupal stage resulted in a significant decrease in BmsGC-α1 expression levels at 48 and 72 h postinjection. After silencing BmsGC-α1, both the egg-laying amount and hatching rate of silkworm eggs were significantly reduced compared to the control group. These results suggest that BmsGC-α1 plays an important role in regulating the reproductive system of silkworms. This finding enhances our understanding of the functional diversity of sGC in insects.