Free circular introns with an unusual branchpoint in neuronal projections

Abstract
Data availability
Article and author information
Metrics

Abstract

The polarized structure of axons and dendrites in neuronal cells depends in part on RNA localization. Previous studies have looked at which polyadenylated RNAs are enriched in neuronal projections or at synapses, but less is known about the distribution of non-adenylated RNAs. By physically dissecting projections from cell bodies of primary rat hippocampal neurons and sequencing total RNA, we found an unexpected set of free circular introns with a non-canonical branchpoint enriched in neuronal projections. These introns appear to be tailless lariats that escape debranching. They lack ribosome occupancy, sequence conservation, and known localization signals, and their function, if any, is not known. Nonetheless, their enrichment in projections has important implications for our understanding of the mechanisms by which RNAs reach distal compartments of asymmetric cells.

Data availability

All raw data (fastq format) and corresponding coverage files (bigwig format) are available at NCBI GEO under accession number GSE129924, and a tarball of supplementary tables and code is at http://eddylab.org/publications.html#Saini19.

The following data sets were generated

1. Saini H
(2019) Free circular introns with an unusual branchpoint in neuronal projections
NCBI Gene Expression Omnibus, GSE129924.

https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE129924

Article and author information

Author details

Harleen Saini

RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States

For correspondence
harleen.saini@umassmed.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-6954-4098
Alicia A Bicknell

RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States

Competing interests
The authors declare that no competing interests exist.
Sean R Eddy

Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Harvard University, Cambridge, United States

For correspondence
seaneddy@fas.harvard.edu

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-6676-4706
Melissa J Moore

RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States

For correspondence
melissa.moore@umassmed.edu

Competing interests
The authors declare that no competing interests exist.

Funding

National Institute of General Medical Sciences (R01-GM53007)

Melissa J Moore

Howard Hughes Medical Institute

Sean R Eddy
Melissa J Moore

Howard Hughes Medical Institute (International Student Research Fellowship)

Harleen Saini

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. Animals were handled in accordance with protocols approved by the Institutional Animal Careand Use Committees at University of Massachusetts Medical School (docket #A-2245-16) and Harvard University (protocol #10-16-1). All surgery was performed after euthanization, and every effort was made to minimize suffering.

Copyright

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.