Dpp-mediated TGF-β signaling regulates vitellogenesis through 20-hydroxyecdysone signaling in the cabbage beetle, Colaphellus bowringi

Pestic Biochem Physiol. 2023 Dec:197:105706. doi: 10.1016/j.pestbp.2023.105706. Epub 2023 Nov 23.

Abstract

The Dpp signaling, as one of the branches within the TGF-β superfamily, plays a crucial role in regulating various biological processes in insects. However, its impact on female reproduction through vitellogenesis remains unclear. In this study, the expression profiles implied that the Dpp signaling genes, including Dpp, Punt, Mad, and Medea, were up-regulated during reproductive development in the ovary of Colaphellus bowringi. Knockdown of these five Dpp signaling genes revealed significant effects of Dpp, Tkv, Mad, and Medea on ovarian development through vitellogenesis in the fat body. Our finding further indicated that Dpp signaling influences the expression of 20-hydroxyecdysone (20E) receptor and responsive genes in the fat body. Additionally, knockdown of 20E receptor EcR resulted in similar phenotypes as observed in the Dpp pathway genes knockdown, implying a regulatory role for Dpp signaling via EcR in vitellogenesis. Furthermore, knocking down Dpp, Tkv, and EcR in female adults led to a reduction in total dry weight and protein content, as well as the expression of mTOR, a factor linked to protein intake. These results suggest that the Dpp signaling pathway modulates vitellogenesis by impacting the AA/TOR-mediated 20E pathway in the fat body, providing novel insights into the network governing insect reproduction and offering potential targets for controlling female pest reproduction.

Keywords: Dpp; EcR; Reproduction; TGF-β; Vitellogenesis.

MeSH terms

  • Animals
  • Brassica* / metabolism
  • Coleoptera* / genetics
  • Coleoptera* / metabolism
  • Ecdysterone / metabolism
  • Female
  • Insect Proteins / metabolism
  • Signal Transduction
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism
  • Vitellogenesis

Substances

  • Ecdysterone
  • Transforming Growth Factor beta
  • Insect Proteins