Cis-interactions between Delta and Notch modulate neurogenic signalling in Drosophila

Area of Science:

• Developmental Biology
• Cell Signaling

Background:

• The Notch signaling pathway is crucial for cell fate determination during development.
• Delta and Serrate are ligands that activate the Notch pathway, mediating cell-cell communication.

Purpose of the Study:

• To investigate the role of Delta and Serrate signaling in the transformation of pre-trichogen cells to tormogen cells in developing bristle organs.
• To elucidate the mechanisms of Notch pathway involvement and the influence of Fringe protein on this process.

Main Methods:

• Ectopic expression of Delta and Serrate in developing bristle organs.
• Utilizing a dominant-negative form of Notch (ECN) to study autonomous interference.
• Analyzing the effects of Fringe protein on Delta- and Serrate-mediated signaling.

Main Results:

• Ectopic Delta or Serrate induced non-autonomous cell transformation.
• The frequency of transformation depended on ectopic expression levels and endogenous Notch pathway components.
• Delta signaling interference was observed, with reduced endogenous Delta increasing responsiveness and increased Delta decreasing it.
• A dominant-negative Notch form (ECN) autonomously interfered with Delta signal generation, which was restored upon modification of the Notch-binding region.
• Fringe protein interfered with Delta- and Serrate-mediated signaling in bristle organs.

Conclusions:

• Cell-autonomous interactions between Delta and Notch influence signal generation and transduction.
• Fringe protein plays a role in modulating Delta- and Serrate-mediated signaling in bristle organ development, contrary to findings in wing development.