alpha-Fetoprotein (AFP) is an oncofetal antigen believed to play an im
portant role in normal development and carcinogenesis but very little
is known about such a role, We have investigated here the role of AFP
in neural retina development by selectively neutralising AFP in vitro.
AFP has been immunohistochemically located in different cells and lay
ers of the retina during its development, 4-day-old embryos being the
earliest developmental stage when AFP is detected in the growing gangl
ion cell layer, Seven-day-retinae treated with antibodies to AFP in or
gan culture for 3 days did not continue to develop in the same way tha
t they do in the egg, Neither the plexiform layers nor the buds of pho
toreceptor cells were observed after this culture period, In contrast,
7-day retinae cultured in the presence of non-immune serum developed
in a manner similar to retinae in ovo, We present here the first evide
nce, derived by selectively blocking AFP in vitro with specific antibo
dies for an essential role of AFP in the normal development of the chi
ck retina.