Reviewer #1 (Public Review): Live imaging of Alu elements reveals non-uniform euchromatin dynamics coupled to transcription
Year: 2024
Type: peer-review
Abstract: Chromatin structure and dynamics are crucial for eukaryotic nuclear functions.Hi-C and related genomic assays have revealed chromatin conformations, such as A/B compartments, in fixed cells, but the dynamic motion of such structures is not well understood.Moreover, elucidating the relationship between the motion of chromatin and transcriptional activity is hampered by a lack of tools for specifically measuring the mobility of active euchromatin.Here, we introduce a CRISPR-based strategy for live imaging of the gene-rich A compartment by labeling Alu elements -a retrotransposon family enriched within the transcriptionally active A compartment.Surprisingly, within euchromatin, microscopy analysis reveals that Alu-rich regions do not correlate with lower local H2B density, and form irregular foci of a few hundred nanometers in diameter, underscoring the heterogeneity of euchromatin organization.Alu-rich (gene-rich) chromatin is also more mobile than Alu-poor (gene-poor) chromatin, and transcription inhibition by actinomycin D results in decreased chromatin mobility of Alu-rich regions.These observations highlight the complexity of chromatin organization and dynamics and connect them to transcriptional activity on a genome-wide scale. eLife assessmentThis valuable study establishes a method for live-cell imaging, tracking, and quantification of Alu elements marking euchromatic regions of the nucleus.The method will help characterize the relationship between chromatin dynamics and transcriptional activity.While the findings are largely consistent with previous reports, characterization of the technique is incomplete and could benefit from additional controls.
Source: eLife
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,500
Funders: National Science Foundation, Howard Hughes Medical Institute, Princeton University, Rutgers Cancer Institute of New Jersey, Princeton Center for Complex Materials, Materials Research Science and Engineering Center, Harvard University, Multidisciplinary University Research Initiative, National Cancer Institute, Division of Materials Research, Air Force Office of Scientific Research
OpenAlex ID: W4399321392