Gene expression in response to retinoic acid in novel human chromosome 21 monochromosomal cell hybrids

To access a wide variety of expressed sequences from human chromosome 21 we have placed this chromosome into undifferentiated P19 mouse embryonic carcinoma cells. Cell lines resulting from these experiments have a range of morphologies and a wide variety of karyotypes. We have studied the retinoic acid response of five cell lines, compared to P19 cells, by observing three markers of retinoic acid induced P19 differentiation-cell morphology, RAR alpha and Wnt1 transcription. We see an 'early' retinoic acid response effect, however this response breaks down by the time the 'late' gene Wnt1 would be transcribed in P19 cells. A highly responsive cell line will be useful for cloning expressed sequences from human chromosome 21 which are produced by early genes in retinoic acid inducible pathway, such as those involved in neurogenesis.