NON-CODING RNAS IN STEM CELL AND GERMLINE BIOLOGY: THE LONG AND THE SHORT OF IT

Abstract

THIS THESIS EXAMINES NON-CODING RNAS IN STEM CELL AND GERMLINE BIOLOGY. IT INCLUDES A STUDY ON A CLASS OF STEM CELL AND GERMLINE?ENRICHED SMALL RNAS KNOWN AS PIWI-INTERACTING RNAS (PIRNAS) AND THEIR PIWI PROTEIN PARTNERS IN THE BASAL METAZOAN, HYDRA. RESULTS INDICATE THAT VARIOUS CONSERVED FEATURES OF PIWI PROTEINS AND THE PIRNA PATHWAY WERE LIKELY ESTABLISHED BEFORE BILATERIAN EVOLUTION. THIS THESIS ALSO INCLUDES A STUDY ON LONG NON-CODING RNAS IN THE DROSOPHILA GERMLINE, INCLUDING GERMLINE STEM CELLS (GSCS). INITIAL OBSERVATIONS REVEALED THAT OVARIAN LNCRNA EXPRESSION EXHIBITS A GSC-BIAS, WHICH IS NOT SEEN IN PROTEIN-CODING TRANSCRIPTS, SUGGESTING THAT MANY FEMALE GERMLINE LNCRNAS MIGHT BE INVOLVED IN GSC MAINTENANCE AND DIFFERENTIATION. FEMALE GERMLINE LNCRNAS ALSO POSSESS GREATER SPLICING COMPLEXITY AND DIFFERENTIAL PROMOTER SWITCHING BETWEEN UNDIFFERENTIATED AND DIFFERENTIATED GERMLINE CELLS THAN DO PROTEIN-CODING GENES, UNVEILING A NEW FEATURE OF OVARIAN LNCRNAS.