The eyes absent gene: genetic control of cell survival and differentiation in the developing Drosophila eye.

The eyes absent (eya) gene is required at an early stage in development of the D. melanogaster compound eye. In eya mutants, progenitor cells in the eye disc undergo programmed cell death anterior to the morphogenetic furrow, rather than proceeding into the pathway of retinal differentiation. A low level of cell death normally occurs at this stage, suggesting that eya activity influences the distribution of cells between differentiation and death. Molecular analysis identifies a nuclear protein expressed in progenitor cells prior to differentiation. Transformation with the cDNA prevents progenitor cell death and allows the events that generate the eye to proceed. eya activity is required for the survival of eye progenitor cells at a critical stage in morphogenesis.