Knockdown of LmSPARC influences lipid metabolic homeostasis involved ovarian development in Locusta migratoria.

Reproduction, a fundamental feature of all known life, is closely correlated with energy homeostasis. Lipids, which can accumulate, provide essential energy support for reproduction. Secreted Protein, Acidic and Rich in Cysteine (SPARC) is a cellular matrix glycoprotein involved in the regulation of extracellular matrix synthesis. However, the precise coordination of lipid homeostasis by SPARC during insect reproductive development remains poorly understood. Our study revealed that when the expression of LmSPARC was downregulated by RNA interference (RNAi) in 4th and 5th instar nymphs, molting was delayed compared with that in the control. Knockdown of LmSPARC reduced levels of vitellogenin (Vg) protein and retarded maturation of oocytes. The intercellular patency in the follicular epithelium of the ovaries was abnormal after LmSPARC silencing. In addition, transcriptomic and metabolomic analyses showed that the energy metabolism pathway was disrupted in locusts lacking LmSPARC, and the accumulation and degradation of lipids in the body were abnormal. This study provides insights into the effects of LmSPARC on ovarian development and energy metabolism homeostasis in Locusta migratoria, and provides a reference for screening biological control targets via on RNAi.