Seven up regulates reproductive diapause initiation via juvenile hormone biosynthesis in the cabbage beetle
Kou Wang1, Yu-Lian Zhao1, Yan-Zi Jiang1
1Hubei Key Laboratory of Resources Utilization and Sustainable Pest Management, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Abstract:
Reproductive diapause is an insect survival strategy in which reproduction temporarily halts in response to adverse environmental changes. This process is characterized by arrested ovarian development and lipid accumulation in females. A reduction in juvenile hormone (JH) biosynthesis is known to initiate reproductive diapause, but its regulatory mechanism remains unclear. Seven up (Svp), a transcription factor from the nuclear receptor family, plays a crucial role in various developmental processes in insects. In this study, using the cabbage beetle Colaphellus bowringi as a model, we observed higher expression of Svp in the heads of female adults under reproductive photoperiodic conditions (short-day [SD]) compared to diapause conditions (long-day [LD]). RNA interference-mediated knockdown of Svp in SD females induced typical diapause phenotypes, including ovarian arrest and lipid accumulation. The application of methoprene (ME), a JH receptor agonist, reversed these diapause phenotypes and restored reproduction, indicating that Svp's regulation of reproductive diapause is dependent on JH signaling. Additionally, Svp knockdown led to the downregulation of JH pathway genes and a reduction in JH titers. Further evidence suggested that Svp regulates the expression of JHAMT1, a critical gene in JH biosynthesis, which determines diapause entry in C. bowringi. These findings suggest that diapause-inducing photoperiods suppress Svp expression, blocking JH production and triggering diapause. This work reveals a critical transcription factor that regulates reproductive diapause initiation through modulating JH production, providing a potential target for controlling pests capable of entering reproductive diapause.
Insights
The transcription factor Seven up (Svp) regulates insect reproductive diapause by controlling juvenile hormone (JH) production. Suppressing Svp triggers diapause, offering a new pest control target.
Area of Science:
- Entomology
- Molecular Biology
- Insect Physiology
Background:
- Reproductive diapause is a survival strategy in insects, involving halted reproduction and ovarian development.
- Juvenile hormone (JH) biosynthesis reduction initiates diapause, but its regulation is not fully understood.
Purpose of the Study:
- To investigate the role of the transcription factor Seven up (Svp) in regulating reproductive diapause in insects.
- To elucidate the molecular mechanisms by which Svp influences JH signaling and diapause.
- To identify potential targets for pest control.
Main Methods:
- Studied the cabbage beetle (Colaphellus bowringi) as a model organism.
- Analyzed Svp gene expression under different photoperiodic conditions.
- Utilized RNA interference (RNAi) to knock down Svp expression.
- Assessed the effects of methoprene (a JH agonist) on diapause phenotypes.
Main Results:
- Svp expression was higher under short-day (reproductive) conditions than long-day (diapause) conditions.
- Svp knockdown in short-day conditions induced diapause phenotypes (ovarian arrest, lipid accumulation).
- Methoprene treatment reversed Svp knockdown-induced diapause, confirming JH dependency.
- Svp knockdown reduced JH pathway gene expression and JH titers, including regulation of JHAMT1.
Conclusions:
- Diapause-inducing photoperiods suppress Svp expression, leading to reduced JH production and diapause entry.
- Svp acts as a key regulator of reproductive diapause initiation by modulating JH biosynthesis.
- Svp represents a potential molecular target for managing insect pests exhibiting reproductive diapause.
More Related Videos
08:53Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System
Published on: September 6, 2016
10:14Double-stranded RNA Oral Delivery Methods to Induce RNA Interference in Phloem and Plant-sap-feeding Hemipteran Insects
Published on: May 4, 2018
