Conserved and divergent elements in Torso RTK activation in Drosophila development

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Signalling pathways are frequently reused across different biological processes.
• The mechanisms by which these pathways are co-opted remain incompletely understood.

Purpose of the Study:

• To investigate the mechanisms of repeated activation of the Drosophila Torso receptor in embryogenesis and pupariation.
• To identify factors contributing to the context-specific co-option of signalling pathways.

Main Methods:

• Analysis of Drosophila Torso receptor activation during embryogenesis and pupariation.
• Investigating the role of Torso-like and other proteins in Torso activation.
• Examining enhancer elements controlling torso-like gene expression.

Main Results:

• Torso activation in both embryogenesis and pupariation requires the Torso-like protein.
• Distinct enhancers regulate torso-like expression in embryogenesis versus pupariation.
• Different sets of proteins are recruited for Torso activation in each context.

Conclusions:

• Repeated Torso receptor activation is facilitated by ligand gene duplication and differential expression.
• Acquisition of distinct enhancers for torso-like and recruitment of context-specific proteins allow pathway reuse.
• These mechanisms enable a single receptor to be activated in diverse biological contexts.