The Exon Junction Complex is Required for Stem and Progenitor Cell Maintenance in Planarians
Overview
Reproductive Medicine
Affiliations
Named for its assembly near exon-exon junctions during pre-mRNA splicing, the exon junction complex (EJC) regulates multiple aspects of RNA biochemistry, including export of spliced mRNAs from the nucleus and translation. Transcriptome analyses have revealed broad EJC occupancy of spliced metazoan transcripts, yet inhibition of core subunits has been linked to surprisingly specific phenotypes and a growing number of studies support gene-specific regulatory roles. Here we report results from a classroom-based RNAi screen revealing the EJC is necessary for regeneration in the planarian flatworm Schmidtea mediterranea. RNAi animals rapidly lost the stem and progenitor cells that drive formation of new tissue during both regeneration and cell turnover, but exhibited normal amputation-induced changes in gene expression in differentiated tissues. Together with previous reports that partial loss of EJC function causes stem cell defects in Drosophila and mice, our observations implicate the EJC as a conserved, posttranscriptional regulator of gene expression in stem cell lineages. This work also highlights the combined educational and scientific impacts of discovery-based research in the undergraduate biology curriculum.
piRNA generation is associated with the pioneer round of translation in stem cells.
Parambil S, Li D, Zelko M, Poulet A, van Wolfswinkel J Nucleic Acids Res. 2023; 52(5):2590-2608.
PMID: 38142432 PMC: 10954484. DOI: 10.1093/nar/gkad1212.
The Physiological Roles of the Exon Junction Complex in Development and Diseases.
Asthana S, Martin H, Rupkey J, Patel S, Yoon J, Keegan A Cells. 2022; 11(7).
PMID: 35406756 PMC: 8997533. DOI: 10.3390/cells11071192.
Defined diets for freshwater planarians.
Abel C, Powers K, Gurung G, Pellettieri J Dev Dyn. 2021; 251(2):390-402.
PMID: 34258816 PMC: 8758798. DOI: 10.1002/dvdy.400.
Salamander-like tail regeneration in the West African lungfish.
Verissimo K, Perez L, Dragalzew A, Senevirathne G, Darnet S, Barroso Mendes W Proc Biol Sci. 2020; 287(1935):20192939.
PMID: 32933441 PMC: 7542818. DOI: 10.1098/rspb.2019.2939.