Sonic Hedgehog is not a limb morphogen but acts as a trigger to specify all digits.
Jianjian Zhu, Rashmi Patel, Anna Trofka, Brian D. Harfe, Susan Mackem
This study shows Sonic Hedgehog (Shh) acts as a trigger for digit specification through a relay network rather than as a traditional morphogen.
Developmental Cell · Aug 16, 2022Peer-reviewedDevelopmental Biology