DAUGHTERLESS IS REQUIRED FOR THE EXPRESSION OF CELL-CYCLE GENES IN PERIPHERAL NERVOUS-SYSTEM PRECURSORS OF DROSOPHILA EMBRYOS

The function of the neuronal differentiation gene daughterless (da) is required for the proper initiation of neuronal lineage development in all PNS lineages following the selection of neuronal precursor cells. Previous studies have shown that the ubiquitously expressed da protei n is required for the proper expression of neuronal precursor genes an d lineage identity genes in the PNS of Drosophila melanogaster embryos . These genes are required for differentiation and cell fate determina tion in the developing PNS. These findings, however, did not explain t he failure of the nascent PNS precursors to undergo a normal cell cycl e and divide. Here we show that four genes whose products are required for various stages of the cell cycle are misexpressed in the PNS of d a mutant embryos. This suggests that all aspects of PNS precursor diff erentiation examined so far are under the transcriptional control of d a. (C) 1997 Wiley-Liss, Inc.