CDON contributes to Hedgehog-dependent patterning and growth of the developing limb

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Hedgehog (HH) signaling regulates embryonic development, controlling cell behaviors like fate, proliferation, migration, and survival.
• HH ligands interact with PTCH1 and co-receptors GAS1, CDON, and BOC.
• Previous studies showed overlapping roles for these co-receptors, but early lethality prevented assessing their collective role in later development, particularly limb development.

Purpose of the Study:

• To investigate the collective role of GAS1, CDON, and BOC co-receptors in embryonic limb development.
• To determine their contribution to digit specification, limb patterning, and long bone growth.

Main Methods:

• Limb-specific conditional deletion of Cdon in a Gas1;Boc null mutant background.
• Analysis of limb development, digit formation, and long bone patterning in the generated mutants.

Main Results:

• Combined genetic deletion of Gas1, Cdon, and Boc in the developing limb leads to significant digit loss.
• Limb outgrowth and long bone patterning are severely affected in these mutants.
• These findings highlight a critical collective function of these co-receptors in limb morphogenesis.

Conclusions:

• GAS1, CDON, and BOC act collectively and are essential for HH-dependent limb patterning and growth.
• This study elucidates the indispensable collaborative function of these co-receptors in a key developmental process.