| Popis: |
SUMMARY Myelin, a specialized membrane produced by oligodendrocytes, insulates and supports axons. Oligodendrocytes extend numerous cellular processes to wrap multiple axons, and myelin sheaths differ in length and thickness. Notably, neuronal activity can modify sheath characteristics. How myelin formation is controlled at sites distant from oligodendrocyte cell bodies is not well known. Using zebrafish, we tested the possibility that 3’ untranslated regions (UTRs) influence localization of myelin mRNAs, thereby enabling localized gene expression. By visualizing mRNA in living animals, we found that some candidate 3’ UTRs were enriched in myelin sheaths and localized near growth zones of nascent myelin membrane. Injecting zebrafish larvae with tetrodotoxin to block action potentials reduced the amounts of mRNAs localized to myelin in a 3’ UTR-dependent manner. Our data indicate that 3’ UTRs contain information for neuronal activity-regulated localization of mRNAs to myelin, suggesting that changes in sheath characteristics result from mRNA regulation within nascent sheaths. |
