Fig. 3

Frem2-KO mice lack eyelids and develop blood-filled blisters covering their eyes. A Gross image of an E15 Frem2^+/+ fetus with a normal eye. A Frem2^-/- fetus (below) with a blood-filled blister (arrowhead) covering the eye. B Hematoxylin and eosin-stained coronal head section of a Frem2^+/- E15 fetus and a higher magnification image below display normal eyelid morphology. C Histological section of a Frem2^-/- E15 fetus with a blood-filled blister, and a higher magnification image displays the absence of the cornea and eyelid. D Low- and high-magnification histology images of a Frem2^-/- E16 fetus show a normal right eyelid and a hemorrhage covering the left eyelid. E Gross images of Frem2^+/+ and Frem2^+/- P0 pups show normal eyelids. F Gross images of Frem2^-/- P0 pups display missing eyelids (arrowhead). G Histology sections of P0 Frem2^+/+ and Frem2^+/- heads show normal eyelids, with corresponding higher magnification images of the right (R) and left (L) eyes presented below. H Histology section of a P0 Frem2^-/- pup shows thinning of the eyelid (R) and a missing eyelid with a hemorrhage over the eye (L). I Images from a newborn Frem2^-/- pup show a missing eyelid (R) and thinning of the eyelid (L). J Images from a Frem2^-/- pup show a missing eyelid (R) and a normal contralateral eyelid (L). Scale bars: A: 2 mm, B–G: 1 mm, H–J: 1 mm.