Poster abstracts
Poster number 44 submitted by Thomas Gallagher
Features of oscillatory transcript 3’UTRs regulate Pnrc2-mediated decay during zebrafish somitogenesis
Thomas L. Gallagher (Molecular Genetics & the Center for RNA Biology, The Ohio State University), Kiel T. Tietz (Molecular Genetics & the Center for RNA Biology, The Ohio State University), Monica C. Mannings (Molecular Genetics & the Center for RNA Biology, The Ohio State University), Zachary T. Morrow (Molecular Genetics, The Ohio State University), Nicolas L. Derr (Molecular Genetics, The Ohio State University), Sharon L. Amacher (Molecular Genetics, Center for RNA Biology, Biological Chemistry & Pharmacology, Center for Muscle Health & Neuromuscular Disorders, The Ohio State University)
Abstract:
Vertebrate segmentation is controlled by the segmentation clock, a molecular oscillator that regulates gene expression and cycles rapidly. Oscillating genes include her/Hes genes, which encode transcriptional repressors that auto-inhibit their own expression, and deltaC (dlc), which encodes a Notch ligand that mediates cellular signalling. Oscillatory transcripts are cleared rapidly, and this depends upon the gene pnrc2 that encodes an mRNA decay adaptor. Previously, we showed the her1 3’UTR confers instability to otherwise stable transcripts in a Pnrc2-dependent manner (Gallagher et al, 2017), however, the molecular mechanism(s) by which oscillatory transcripts are cleared remained largely unknown. To identify cis-regulatory features residing in the her1 3’UTR that are critical for Pnrc2-mediated decay, we developed transgenic inducible zebrafish reporter lines containing varied her1 3’UTR regions. We find that the last 179 nucleotides (nts) is necessary and sufficient to confer Pnrc2-dependent reporter mRNA decay in developing embryos. Motif analysis reveals a Pumilio response element (PRE) and AU-rich element (ARE) within the last 179 nts of the her1 3’UTR, both of which are required for rapid turnover of reporter mRNA in vivo. Similar to the her1 3’UTR, the dlc 3’UTR confers instability to reporter mRNA and also contains PRE and ARE motifs, suggesting that a common mechanism may underlie rapid oscillatory transcript decay. Our findings implicate factors including Pumilio (Pum) and AU-rich binding proteins (ARE-BPs) as regulators of oscillatory transcript decay during somitogenesis and we are currently taking genetic approaches to investigate the post-transcriptional regulatory role of Pum and ARE-BPs for oscillatory expression. Overall, our goal is to define post-transcriptional regulatory mechanisms that promote oscillatory expression during vertebrate segmentation.
References:
Gallagher, TL, Tietz, KT, Morrow, ZT, McCammon, JM, Goldrich, ML, Derr, NL, Amacher, SL. Pnrc2 regulates 3'UTR-mediated decay of segmentation clock-associated transcripts during zebrafish segmentation. Dev Biol. 2017; 429 (1), 225-239.
Keywords: segmentation, mRNA decay, pumilio