THE DROSOPHILA STONEWALL GENE ENCODES A PUTATIVE TRANSCRIPTION FACTORESSENTIAL FOR GERM-CELL DEVELOPMENT

The differentiation of Drosophila germ cells is a useful model for stu dying mechanisms of cell specification. We report the identification o f a gene, stonewall, that is required for germ cell development. Mutat ions in stonewall block proper oocyte differentiation and frequently c ause the presumptive oocyte to develop as a nurse cell. Eventually, ge rm cells degenerate apoptotically. Stonewall is a germ cell nuclear pr otein; Stonewall has a DNA binding domain that shows similarities to t he Myb and Adf-1 transcription factors and has other features that sug gest that it is a transcription activating factor. We suggest that Sto newall transcriptional regulation is essential in cystocytes for matur ation into specialized nurse cells and oocyte.