Book of Abstracts: Albany 2007
June 19-23 2007
Characterization of short RNA clones in the Sfmbt2 locus
Short RNAs are known to control gene expression at several different levels in organisms ranging from yeast to plants to mammals. To understand the role of short RNAs in regulating the development of mammalian cells, we have comprehensively profiled short RNA expression from several distinct stages of murine T-lymphocyte development. While the majority of the clones correspond to known miRNAs, novel short RNAs constitute 10% of the cloned sequences. We mapped novel short RNA sequences to their physical location in the mouse genome. Several highly related novel sequences clustered in an intron of the uncharacterized gene Sfmbt2 on mouse chromosome 2. The dynamics of Sfmbt2 expression and cloning frequency of members of the cluster throughout T lymphocyte development are highly correlated, suggesting that the novel RNA sequences derived from the cluster are controlled by the Sfmbt2 promoter. The Sfmbt2 short RNAs are similar to known miRNAs; most of them can fold into miRNA-like hairpins, and the processing of these species is dependent on Dicer. However, while highly related miRNAs are well conserved at the 5? end, the Sfmbt2 short RNAs share a 12-nt consensus motif spanning nucleotides 6 to 17 of most of the sequences. We are actively investigating whether these species are incorporated in the canonical RNAi pathway, and whether they play a role in the maturation of T lymphocytes.
Grace X.Y. Zheng1, 2
1Center for Cancer Research; 2Computational and Systems Biology; 3Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA