In looking for genes encoding RNA-binding factors, we prepared an expression library in lambda gt11, by cloning cDNAs corresponding to the polyadenylated fraction of RNA from rat brain at the embryonal day 18. The library was then screened by binding to a radioactive RNA, transcribed in vitro from a cDNA encoding the rat histone variant H3.3. Here we report some findings concerning a cDNA for a protein which contains two putative double stranded RNA-binding domains (dsBD). The corresponding message is specifically expressed in the brain. Moreover, Southern blot analysis showed that the gene is highly conserved from Drosophila melanogaster to man.