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Trisomies Reorganize Human 3D Genome.
Irina V Zhegalova1,2, Petr A Vasiluev3, Ilya M Flyamer4
1Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia.
International Journal of Molecular Sciences
|November 25, 2023
Summary
Trisomy, the presence of an extra chromosome, alters 3D genome organization. This study reveals how extra chromosomes impact chromatin structure and gene expression in conditions like Patau and Edwards syndromes.
Area of Science:
- Genetics
- Molecular Biology
- Developmental Biology
Background:
- Trisomy involves an extra chromosome copy, causing severe developmental issues in humans.
- Trisomies lead to widespread gene expression alterations beyond the extra chromosome.
Purpose of the Study:
- To investigate the 3D chromatin structure in human cells with trisomy 13, 16, and 18.
- To understand how extra chromosomes influence genome-wide gene expression dysregulation.
Main Methods:
- Utilized high-throughput chromosome conformation capture (Hi-C) technique.
- Analyzed chromatin 3D structure in chorion cells (trisomy 13, 16) and fibroblasts (trisomy 18).
Main Results:
- Extra chromosomes systematically alter contact frequencies between chromosomes.
- Specific chromosomes show stochastic changes in contact patterns, linked to lamina-associated domains (LADs) and gene content.
- Compacted genomic regions in trisomic cells are enriched in housekeeping genes, suggesting reduced accessibility and transcription.
Conclusions:
- The 3D organization of chromatin is significantly altered in human trisomies.
- Changes in chromatin structure provide a mechanism for pan-genome transcription dysregulation in trisomic conditions.
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