Up-regulation of the Ku heterodimer in Drosophila testicular cyst cells

In Drosophila, developing germline cysts in testis are enveloped by two somatic cyst cells essential for germline development and male reproduction. The cyst cells continue development along with the germline. However, the mechanisms of somatic gene expression in testes are poorly understood. We report transcriptional up-regulation of the Ku heterodimer in cyst cells. The initial up-regulation is independent of germline, and transcription is further augmented during spermatogenesis. Abundance of Ku in the cyst cell cytoplasm suggests the role for Ku subunits in the regulation of sperm individualization.