Biphasic subcellular localization of the DAZL-related protein boule in Drosophila spermatogenesis

The Drosophila boule gene is expressed exclusively in the male germline and encodes an RNA binding protein closely related to the mammalian fertility factors encoded by the DAZ (Deleted in Azoospermia) and DAZL (DAZ-like) gen es. Mutation of boule blocks both meiotic divisions. Differentiation noneth eless continues, resulting in tetraploid spermatids that fail to mature int o sperm. We have found that Boule localizes premeiotically to a perinucleol ar region and then translocates to the cytoplasm at the onset of meiosis. W e show that deletion of the Y chromosome ks-1 fertility locus eliminates Bo ule nuclear localization, although it does not perturb entry into meiosis. Based on these observations we propose that Boule acts in the cytoplasm to regulate the stability or translation of messenger RNA encoding an essentia l meiotic factor. (C) 1998 Academic Press.