Endocrine gland growth as the developmental switch for insect diapause - PubMed
5 hours ago
- #juvenile hormone
- #insect diapause
- #photoperiod
- Endocrine gland growth acts as a developmental switch for insect diapause, particularly in the cabbage beetle (Colaphellus bowringi).
- Diapause is triggered by suppressed juvenile hormone (JH) production from the corpora allata (CA), influenced by seasonal photoperiod.
- Under long-day (LD) conditions, the CA and its nuclei are smaller compared to short-day (SD) conditions, affecting JH biosynthesis.
- Transcriptomic analysis identified CA-enriched and photoperiod-responsive transcripts, including those linked to DNA replication.
- RNAi screening revealed two key factors, retained (retn) and ventral veins lacking (vvl), promoting DNA replication, CA growth, and JH production.
- Retn functions upstream of vvl, both activating extra macrochaetae (emc), which further promotes CA growth.
- Silencing retn, vvl, or emc reduces CA size, lowers JH levels, and induces diapause-like effects, reversible by JH analog methoprene.
- The study provides genetic evidence that endocrine organ growth is a causal switch for seasonal diapause.