Development of differential affinities and positional information in embryonic retina cells: inhibition by BrdU

Embryonic neural retina cells fail to develop surface properties for type-specific cell recognition if they are transiently exposed to BrdU during an early, critical age. Such cells do not proceed with histogenetic positioning, organization and differentiation and, instead, form a malformed cell mass. This effect of BrdU is correlated with BrdU incorporation into DNA, and it can be prevented by simultaneous treatment of the cells with cytosine arabinoside. The proposed working hypothesis is that, in this system, BrdU interferes with expression of genes controlling cognitive specification of the cell surface.