BMP and Hedgehog signaling during the development of scleral ossicles

► Ptc1 is expressed in a wider temporal and spatial domain than shh.► Ihh is expressed in a similar expression domain as ptc1 but a narrower temporal window. ► Inhibition of BMPs prevents ossicle development. ► Bmp2 is involved in ossicle development. ► Inhibition of the BMP family decreases the expression of ihh in the scleral mesenchyme.