FLRT3 as a key player on chick limb development

► Flrt3 expression during limb development is restricted to the AER. ► Flrt3 expression coincides with that of fgf8 and pERK activity. ► Flrt3 is necessary but not sufficient for proper AER formation and maintenance. ► Flrt3 expression is not regulated by FGF activity. ► Ectopic Wnt3a is able to induce flrt3; BMPs specifically inhibit flrt3 in the AER.