W016 Transcriptome Diversity through Alternative and Antisense Polyadenylation

Date: Sunday, January 15, 2012
Time: 5:05 PM
Room: Royal Palm Salon 1-2
Quinn Li , Miami University, Oxford, OH
Messenger RNA polyadenylation is a critical processing event during eukaryotic gene expression to maintain mRNA stability and ensure its functionality.  The precise location of the poly(A) tail addition, however, is subject to regulation by poly(A) signals and transacting factors.  Alternative polyadenylation (APA) is the use of different poly(A) sites of the same gene to generate different transcripts.  APA has been recognized to regulate gene expression through inclusion or exclusion of regulatory cis-elements resided on the transcripts. APA may generate mRNA encoding different proteins.  Thus, APA, similar to alternative splicing, is another mechanism to produce transcriptome/proteome diversity in eukaryotes in response to developmental and environmental cues. In Arabidopsis we found that over 70% of Arabidopsis genes use APA.  Particularly, significant amount of APA occurs at introns and coding regions, indicative of potential role of modulating gene expression. Polyadenylation of antisense transcripts was recently found to regulate its sense gene expression. We found a few thousand genes possessing antisense poly(A) sites that may play a role in regulating their sense gene expression.  In addition, a mutation of a polyadenylation factor, AtCPSF30, was characterized in terms of its role in APA.  A digital in vivo poly(A) assay using Illumina sequencing revealed the extent of poly(A) profile changes indicative of it’s role in poly(A) site selections.