THE RB97D GENE ENCODES A POTENTIAL RNA-BINDING PROTEIN REQUIRED FOR SPERMATOGENESIS IN DROSOPHILA

Many proteins that bind RNA contain a common RNA-binding domain, the R NP motif. We have been studying two Drosophila RNP motif proteins, Hrb 98DE and Hrb87F, which are hnRNA-binding proteins. We report here the characterization of the Rb97D gene, which encodes a protein that is cl osely related to the Hrb proteins in the RNP motif domain, but has a d istinctive proline-rich C-terminal domain. The gene is located at 97D on the right arm of the third chromosome, near the rough gene. Multipl e transcripts from the Rb97D gene are present at varying levels throug hout development. The transcripts are generated by alternative process ing in the coding and 3' untranslated regions, and can encode two prot ein isoforms. Analysis of a mutant containing a P element inserted int o the 5' untranslated region of the gene demonstrates that Rb97D is re quired for male fertility. Possible models for the function of Rb97D i n testes are discussed.