3Department of Biology [Fort Collins] (Colorado State University
Biology Building, Room 111
1878 Campus Delivery
Fort Collins, CO 80523-1878 - United States)
4Imagerie et Modélisation - Imaging and Modeling (Département Biologie computationnelle,
Département de Biologie cellulaire et Infection,
25-28, rue du docteur Roux, 75724 Paris Cedex 15 - France)
Abstract : Caenorhabditis elegans early embryos generate cell-specific transcriptomes despite lacking active transcription, thereby presenting an opportunity to study mechanisms of post-transcriptional regulatory control. We observed that some cell-specific mRNAs accumulate non-homogenously within cells, localizing to membranes, P granules (associated with progenitor germ cells in the P lineage) and P-bodies (associated with RNA processing). The subcellular distribution of transcripts differed in their dependence on 3'UTRs and RNA binding proteins, suggesting diverse regulatory mechanisms. Notably, we found strong but imperfect correlations between low translational status and P granule localization within the progenitor germ lineage. By uncoupling translation from mRNA localization, we untangled a long-standing question: Are mRNAs directed to P granules to be translationally repressed, or do they accumulate there as a consequence of this repression? We found that translational repression preceded P granule localization and could occur independently of it. Further, disruption of translation was sufficient to send homogenously distributed mRNAs to P granules. These results implicate transcriptional repression as a means to deliver essential maternal transcripts to the progenitor germ lineage for later translation.
Dylan M Parker, Lindsay P Winkenbach, Samuel P Boyson, Matthew N Saxton, Camryn Daidone, et al.. mRNA localization is linked to translation regulation in the Caenorhabditis elegans germ lineage. Development (Cambridge, England), Company of Biologists, 2020, 147 (13), pp.dev186817. ⟨10.1242/dev.186817⟩. ⟨pasteur-02559475v2⟩