| Type | MGI:General | Description | newborn homozygotes display a delay in the outgrowth of the primary vascular plexus in the retina consistent with impaired capillary sprouting at P4, sprouting vessels have not yet formed a capillary plexus and are only just beginning to expand from the optic disc covering only 30%-40% of the area covered in wild-type mice at P4, mutant blood vessel tips are morphologically abnormal and lack the characteristic cytoplasmic extensions observed in wild-type vessels |