The accumulation of delta-crystallin mRNA in transdetermination and transdifferentiation of neural retina cells into lens.

By means of hybridization with DNA complementary to delta-crystallin mRNA (delta-mRNA) sequences (delta-cDNA), the levels of delta-mRNA in three different culture systems of 8-day-old chick embryonic neural retina were determined. After 30 days of culturing in vitro, the level of delta-mRNA in cells cultured under conditions of spreading cultures (SpC) was 50 times higher than in the cells maintained in aggregate cultures (AgC) throughout. When the cells pre-cultivated in SpC for an initial 10 days were transferred into AgC, the delta-mRNA level in 30-day cultures was 40 times higher than that in 3-day SpC. The level of delta-mRNA in neural retina in situ was negligible, but it became detectable in 10-day SpC. The initial appearance of detectable delta-mRNA in 10-day SpC coincides with the timing of 'transdetermination' of neural retina cells into lens cells.