MOLECULAR AND GENETIC ANALYSES OF LAMA, AN EVOLUTIONARILY CONSERVED GENE EXPRESSED IN THE PRECURSORS OF THE DROSOPHILA FIRST OPTIC GANGLION

Drosophila retinal axons trigger both the proliferation of their targe ts, the lamina neurons, as well as the final differentiation and migra tion of the lamina glia. To date, the molecular basis of these interac tions has remained unclear. We have identified a new gene, lamina ance stor (lama). Both the lamina's neural and glial progenitors express ra ma, even though these cells have very different developmental origins. Expression of lama is down-regulated once the precursors begin their differentiation programs. Loss of function mutants are viable and fert ile, and appear to have normally developed visual systems. lama encode s a novel protein that is 74% identical to its D. virilis homologue.