Neural fate specification in Drosophila.

The specification of cell fates, particularly in the nervous system where cell diversity is highest, is a basic problem in developmental biology. Mutational and molecular analyses in Drosophila are uncovering families of genes, many of them transcription factors, that regulate the progressive acquisition of neural traits. These comprise the initial selection of neural precursors from the ectoderm, the implementation of a basic neural fate common to all precursors and the concomitant endowment of each precursor and its progeny with specific fates.