Séminaire IBIP
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)

Jeudi 22 mai 2025 à 14h, Amphi 2 (Bât. 2bis)

Processes shaping mRNA poly(A) tails in Arabidopsis

Dominique Gaglliardi
IBMP – Institut de biologie moléculaire des plantes, Strasbourg

Gene expression is regulated at numerous post-transcriptional steps, that are being characterized for decades in plants. Yet, how mRNA poly(A) tail metabolism contributes to regulating gene expression remains largely unexplored, and is even frequently misunderstood because of erroneous assumptions. The advent of new sequencing technologies developed by PacBio or Oxford Nanopore Technologies (ONT) has revolutionized our ability to investigate the metabolism of poly(A) tails. It is now possible to accurately profile the distribution of poly(A) tail sizes at the transcriptome level. We used Nanopore sequencing to investigate mRNA poly(A) tail regulation in Arabidopsis. Our data reveal both gene-specific and general mechanisms regulating poly(A) tail profiles, and the intimate connection between deadenylation and uridylation, i. e. the addition of one or several uridines at the 3’ end of poly(A) tails. I will particularly discuss how the antagonistic effects of uridylation and deadenylation shape the poly(A) tail profiles of Arabidopsis mRNAs. Of note, the shift in mRNA poly(A) distribution between uridylation and deadenylation mutants is much more pronounced in rosette leaves than in flower buds, indicating that the equilibrium between uridylation and deadenylation can be modulated during development.

Contact: Yann Boursiac