NSF EAPSI 2011 – Japan PI: Kevin G. Nyberg Hosts: Dr. Yuji Kageyama, Dr. Satoru Kobayashi Okazaki Institute for Integrated Bioscience National Institutes of Natural Sciences Analyses of expression and function in two nervous-system specific non-coding RNAs in Drosophila melanogaster Deliberate efforts to map all the functional elements in the genome through efforts like the human ENCODE and Drosophila modENCODE projects have shown that the vast majority of eukaryotic genomes is transcribed into RNA, yet only a small subset of these sequences code for a protein. The functions, if any, of many of these non-coding RNAs (ncRNAs) are unknown, but at least some appear to be developmentally regulated, implying function. In 2005, Inagaki and colleagues identified 33 putative mRNA-like non-coding transcripts that are expressed in unique patterns during embryogenesis of the fruit fly Drosophila melanogaster. A majority of these ncRNAs, including MRE-31 and MRE-32, are restricted to the nervous system, suggesting that they may play roles in regulating neurogenesis. Flies lacking MRE-32 show a delay in adult eclosion. No phenotypes have been described for MRE-31. Over the course of this project, the P.I. confirmed expression patterns of MRE-31 in the central and peripheral nervous systems during Drosophila embryogenesis using in situ hybridizations. Current efforts in the Kageyama group have identified via microarray a large number of differentially expressed genes between wild-type and MRE-32-deficient flies. The P.I. was able to independently validate several of these putative MRE-32 downstream targets as differentially expressed using quantitative-real-time PCR, Northern blots, and in situ hybridizations. Taken together, these experiments have contributed, if even only a small part, to fleshing out the biological roles of these mRNA-like ncRNAs. In addition, the P.I. learned valuable techniques for studying expression and function of ncRNAs from the members of the Kageyama group that will further the research goals of his home lab in the United States.