A microphthalmic strain of mice was used to study immunoresponse of the ret
inoblastoma protein. Comparing wild-type, heterozygote and homozygote micro
phthalmic eyes, we found an increasing labelling of phosphorylated retinobl
astoma protein (pRb) in the retinal pigment epithelium. Additionally, micro
phthalmic eyes expressed pRb in the neuroepithelium. Especially rosettes we
re strongly labelled.