Expression Profiling and Functional Characterization of Trichomonas vaginalis microRNA

MicroRNAs (miRNAs) are a class of small non-protein-coding RNAs transcribed form non-coding regions of the genome. Since their discovery a decade ago, microRNAs (miRNAs) have emerged as major regulators of gene expression in eukaryotes of all kinds. More than 5,000 miRNAs were identified in over 50 organisms ranging from multicellular organisms including humans, flies, nematodes, plants, fishes to viruses (miRBase, V10.1). However, miRNA have never been identified in bacteria and protozoan so far. Our preliminary studies proved that mature miRNA did exist in the parasitic protozoan Trichomonas vaginalis. We identified more than 400 putative miRNA pre-sequences from 70,000 T. vaginalis expressed sequence tags (EST) generated by our group (http://TvXpress.cgu.edu.tw) by using a miRNA Detection Pipeline. The presence of putative miRNAs in ESTs indicted that T. vaginalis may have a different miRNA regulating network compared with multicellular organisms. A small scale miRNA serial analysis of gene expression (miRAGE) experiment also indentified 4 mature miRNA from T. vaginalis which showed significant homology to known miRNAs. By using miRNA specific loop-RT-PCR, we characterized the expression pattern of Tv_mir003. Based on the solid evidences we obtained, we propose to initiate a three years research project to elucidate the miRNA interaction network in T. vaginalis. The specific aims of this project are as followings: (1) Identification of miRNA in T. vaginalis by both bioinformatics and experimental approaches. (2) Generation of a Tv_miRNA Database. (3) Prediction of miRNA targets (4) miRNA Expresssion profiling in trophozoite, pseudocyst and amoeboid form which represent various stages of cell growth and pathogenesis by using Tv_miRNA oligofilter and Solexa sequencing. (6) Over-express or knock down miRNA in T. vaginalis and elucidate its effect on gene and protein expression by Tv cDNA microarray and 2-dimensional gel electrophoresis respectively. (7) Generation of a Tv_miRNA Interaction Network Database The long term goal of this project is to promote the use of T. vaginalis as a model to study miRNA regulation. The huge amount of data generated by the present proposal will be used as basis for further studies. The simple life-cycle and the ease of handling of this protozoan make it a perfect model to study the miRNA interaction network.

Project ID:PC9801-2500
External Project ID:NSC97-2320-B182-011-MY3