Award details

Tuning gene expression through antisense transcript dynamics

Reference	BBS/E/J/000CA510
Principal Investigator / Supervisor	Professor Martin Howard
Co-Investigators / Co-Supervisors	Professor Dame Caroline Dean
Institution	John Innes Centre
Department	John Innes Centre Department
Funding type	Research
Value (£)	191,193
Status	Completed
Type	Institute Project
Start date	01/03/2013
End date	29/02/2016
Duration	35 months

Abstract

The role played by non-coding antisense RNAs (asRNAs) in controlling gene expression is poorly understood. Although much is known at a genomic level about non-coding RNA, mechanistic understanding of its role in the control of specific genes is still lacking. Our objective is therefore to dissect how non-coding asRNA controls quantitative expression of a specific gene, the floral repressor FLC in Arabidopsis. In this system, quantitative control is believed to depend on the differential production of two alternatively polyadenylated antisense transcripts. We will therefore investigate how the choice of polyadenylation site can affect sense transcription. This will be achieved by an iterative combination of mathematical modelling and targeted experiments. Our working hypothesis which we will seek to confirm (or refute) is that the antisense transcripts act in opposing positive feedback loops to generate bistability at an individual FLC locus. Regulatory control is exerted by the fraction of time that a given locus spends in one of the two transcriptional states, with only relatively rare stochastic flips between them. Such positive feedback will depend critically on interactions between antisense transcripts and histone modifying enzymes, whose action may alter the local chromatin landscape, thereby reinforcing one or both of the antisense transcriptional states. This model, which will be simulated numerically to generate rigorous predictions, will be tested by genetic perturbation (e.g. deletion of key methyltransferases), measurement of histone modification/polymerase levels by Chromatin ImmunoPrecipitation, and also by monitoring transcript levels inside individual cells. The latter experiment will directly test the bistability hypothesis. The end result of our work will be a focused, quantitative understanding of asRNA-mediated gene regulation that will serve as a paradigm for how antisense transcripts can mediate quantitative variation in gene expression.

Summary

unavailable

Committee	Not funded via Committee
Research Topics	Plant Science, Systems Biology
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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