DIFFERENTIAL EXPRESSION OF RAR-BETA AND RXR-GAMMA TRANSCRIPTS IN CULTURED CRANIAL NEURAL CREST CELLS

In situ hybridization reveals that RAR-beta and RXR-gamma genes in mes encephalic neural crest cultures are independently regulated. RAR-beta transcripts are found in all cells, with a slight increase in signal/ cell with time in culture. In contrast, the distribution of RXR-gamma transcript is initially uniform but becomes increasingly heterogeneous , so that after 72 h in culture, a significant proportion of cells lac k transcripts while a small subpopulation contains very high levels of message. These differences in the behaviour of the RAR beta and RXR g amma genes in vitro can be related to differences in their expression patterns in vivo.