A novel type of non-coding RNA expressed in the rat brain

We have characterized a novel type of non-coding RNA which consists of tand em repeats of similar sequences, approximately 0.9 kb in size. This RNA, te rmed Bsr (brain specific repetitive) RNA, is encoded at a single locus (6 q 31 --> q32) in the rat genome, where 100 to 150 copies of the 0.9 kb sequen ces are repeated in tandem. Bsr RNA is preferentially expressed in the rat central nervous system (CNS), especially in phylogenetically old structures , such as the pareo- and archicortex, amygdala, thalamus and hypothalamus. In the developing brains, Bsr RNA is expressed in the subsets of differenti ating cells but not in proliferating cells. Despite the finding that Bsr RN A appears to be conserved only among the Rattus species, the specific expre ssion pattern of Bsr RNA suggests that it might have some role in the rat C NS. (C) 1999 Elsevier Science B.V. All rights reserved.