An Evolutionarily Conserved Function of Grainyhead in Orchestrating Insect Wing Development.

Area of Science:

• Developmental Biology
• Genetics
• Entomology

Background:

• Insect appendage development relies on conserved genetic pathways despite evolutionary divergence.
• The role of specific transcription factors in wing morphogenesis remains an active area of research.

Purpose of the Study:

• To identify conserved genetic regulators of insect wing development.
• To investigate the function of the Grainyhead (Grh) transcription factor in wing morphogenesis across different insect species.

Main Methods:

• CRISPR/Cas9 gene editing in Bombyx mori.
• Tissue-specific RNA interference (RNAi) in Drosophila melanogaster.
• Comparative transcriptomics and chromatin immunoprecipitation assays.
• RNAi in the white-backed planthopper (Sogatella furcifera).

Main Results:

• BmGrh knockout in silkworms caused crumpled, non-expandable wings.
• DmGrh knockdown in Drosophila resulted in pupal lethality, sex-biased eclosion, and crumpled wings with polarity defects.
• Loss of Grh function downregulated genes involved in cuticle structure and extracellular matrix organization.
• DmGrh directly regulates cuticle-related genes, with cpr65Ea identified as a key downstream effector.
• SfGrh silencing in planthoppers impaired wing expansion and abolished flight.

Conclusions:

• Grainyhead (Grh) is an evolutionarily conserved regulator of insect wing development.
• Grh plays a critical role in cuticle formation and wing morphogenesis.
• Grh represents a potential genetic target for insect pest management strategies aimed at disrupting flight and dispersal.