3-Hydroxy-3-methyl glutaryl coenzyme A reductase is required for ovarian development in the oriental fruit fly Bactrocera dorsalis (Hendel)

Abstract

Abstract 3-Hydroxy-3-methyl glutaryl coenzyme A reductase (HMGR) is an important rate-limiting enzyme in the mevalonate pathway, which is critical for the synthesis of juvenile hormone and insect development. In this study, a full-length cDNA encoding HMGR (BdHMGR) was cloned from the oriental fruit fly, Bactrocera dorsalis (Hendel). The open reading frame of BdHMGR encoded 928 amino acids and shared a high degree of identity with other known HMGRs. The expression levels of BdHMGR were high during the early and lately pupal stages, and were low at the larval and mid pupal stages. In the adult stages, the highest level of BdHMGR was detected on day-10 of the adult lifecycle, and the expression levels in females were greater than those in males. The highest tissue-specific expression was in the ovary, followed by fat body and other tissues. Injection of double-stranded RNA (dsRNA) of BdHMGR into adult females significantly reduced BdHMGR transcript levels, and inhibited ovarian development and affected the expression of two yolk protein genes. After dissection, we found that one or two of the spheroids of ovaries from the BdHMGR dsRNA-injected flies were amorphous and reduced in size as compared with the controls. The results suggest that BdHMGR is required for ovarian development in B. dorsalis and may be a potential target for pest control.