Organisation and dynamics of individual DNA segments in topologically complex genomes

Fuente: arXiv
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Autores principales: Ramakrishnan, Saminathan, Patnaik, Auro Varat, Grillo, Guglielmo, Tubiana, Luca, Michieletto, Davide
Formato: Preprint
Publicado: 2025
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author Ramakrishnan, Saminathan
Patnaik, Auro Varat
Grillo, Guglielmo
Tubiana, Luca
Michieletto, Davide
author_facet Ramakrishnan, Saminathan
Patnaik, Auro Varat
Grillo, Guglielmo
Tubiana, Luca
Michieletto, Davide
contents Capturing the physical organisation and dynamics of genomic regions is one of the major open challenges in biology. The kinetoplast DNA (kDNA) is a topologically complex genome, made by thousands of DNA (mini and maxi) circles interlinked into a two-dimensional Olympic network. The organisation and dynamics of these DNA circles are poorly understood. In this paper, we show that dCas9 linked to Quantum Dots can efficiently label different classes of DNA minicircles in kDNA. We use this method to study the distribution and dynamics of different classes of DNA minicircles within the network. We discover that maxicircles display a preference to localise at the periphery of the network and that they undergo subdiffusive dynamics. From the latter, we can also quantify the effective network stiffness, confirming previous indirect estimations via AFM. Our method could be used more generally, to quantify the location, dynamics and material properties of genomic regions in other complex genomes, such as that of bacteria, and to study their behaviour in the presence of DNA-binding proteins.
format Preprint
id arxiv_https___arxiv_org_abs_2504_11340
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Organisation and dynamics of individual DNA segments in topologically complex genomes
Ramakrishnan, Saminathan
Patnaik, Auro Varat
Grillo, Guglielmo
Tubiana, Luca
Michieletto, Davide
Soft Condensed Matter
Biological Physics
Capturing the physical organisation and dynamics of genomic regions is one of the major open challenges in biology. The kinetoplast DNA (kDNA) is a topologically complex genome, made by thousands of DNA (mini and maxi) circles interlinked into a two-dimensional Olympic network. The organisation and dynamics of these DNA circles are poorly understood. In this paper, we show that dCas9 linked to Quantum Dots can efficiently label different classes of DNA minicircles in kDNA. We use this method to study the distribution and dynamics of different classes of DNA minicircles within the network. We discover that maxicircles display a preference to localise at the periphery of the network and that they undergo subdiffusive dynamics. From the latter, we can also quantify the effective network stiffness, confirming previous indirect estimations via AFM. Our method could be used more generally, to quantify the location, dynamics and material properties of genomic regions in other complex genomes, such as that of bacteria, and to study their behaviour in the presence of DNA-binding proteins.
title Organisation and dynamics of individual DNA segments in topologically complex genomes
topic Soft Condensed Matter
Biological Physics
url https://arxiv.org/abs/2504.11340