Molecular and cellular mechanisms involved in leg joint morphogenesis

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Insect leg development relies on precise spatial patterning.
• Morphogen gradients and signaling pathways orchestrate developmental processes.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying insect leg patterning and tissue folding.
• To investigate the roles of Dpp, Wg, EGFR, and Notch signaling in leg development.

Main Methods:

• Analysis of gene expression patterns (Hth, Dac, Dll).
• Investigating signaling pathways (Dpp, Wg, EGFR, Notch).
• Studying the role of apoptosis and mechanical forces in tissue morphogenesis.

Main Results:

• Dpp and Wg gradients establish the proximo-distal axis.
• EGFR signaling specifies tarsal segments and Notch activation rings.
• Localized Notch activation induces Dysfusion, controlling apoptosis and RhoGTPase regulators.
• Apoptotic cell-generated forces trigger cytoskeleton reorganization and tissue folding.

Conclusions:

• A complex interplay of morphogen gradients, signaling pathways, and mechanical forces ensures precise leg patterning.
• Localized apoptosis and subsequent mechanical signaling are crucial for inducing tissue folding during leg development.