Localized expression of the Drosophila gene Dxl6, a novel member of the serine/arginine rich (SR) family of splicing factors.

Members of the highly conserved family of serine/arginine rich (SR) splicing factors play an essential role in the recognition of the exonic splicing enhancers that control the choice of splice sites in primary transcripts. Here, we report the cloning and the expression pattern of Dxl6, a novel Drosophila member of this protein family. Dxl6 is located on the second chromosome in a position next to hrp48 and Dwee1. Its intron contains Dnop5, a small nucleolar ribonucleoprotein (snoRNP) which is essential for rRNA-processing. During oogenesis, Dxl6 transcripts are expressed in nurse cells. Transcripts are transported into the oocyte and maintained in a ubiquitous pattern in the egg and early embryo. Zygotic Dxl6 transcripts accumulate in the neuroectodermal region of the gastrulating embryo and become highly enriched in the central nervous system (CNS) and brain of embryos. During larval stages, Dxl6 transcripts are detected in distinct patterns in the developing imaginal discs.