Cell fate is determined when the commitment of cells to a particular f
ate Is autonomously maintained, irrespective of their environment. In
Drosophila, fate determination is maintained through the action of the
Polycomb-group and trithorax-group genes, which are required so that
states of homeotic gene activity are inherited through cell division.
It is shown here that the CURLY LEAF gene of Arabidopsis is necessary
for stable repression of a floral homeotic gene and encodes a protein
with homology to the product of the Polycomb-group gene Enhancer of ze
ste. We suggest that Polycomb-group genes have a similar role in fate
determination in plants and animals.