Integrative analysis of X-chromosome reactivation kinetics in a novel reprogramming system

The reactivation of the inactive X chromosome has the potential to provide a unique system to study the developmentally induced formation of euchromatin. However, insights into this process were hampered by the lack of adequate systems, which would allow the dissection of the process using high-thro...

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Detalles Bibliográficos
Autor: Bauer, Moritz
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/668761
Acceso en línea:http://hdl.handle.net/10803/668761
Access Level:acceso abierto
Palabra clave:Reprogramming
X-chromosome
Reactivation
Pluripotency
Chromatin
Reprogramación
Cromosoma X
Reactivación
Pluripotentia
Cromatina
575
Descripción
Sumario:The reactivation of the inactive X chromosome has the potential to provide a unique system to study the developmentally induced formation of euchromatin. However, insights into this process were hampered by the lack of adequate systems, which would allow the dissection of the process using high-throughput sequencing techniques. Here I describe the development of a novel induced pluripotent stem cell reprogramming system that allows the isolation of cells poised for X-reactivation, subsequently achieving near-deterministic efficiency of X-reactivation. Utilizing this novel system, we were able to reveal that the reactivation of silenced genes occurs rapidly and can be divided into distinct initiation and completion phases. Similarly, we could show that chromatin opening of the inactive X proceeds in a two-step fashion, initiating in close proximity to previously open regions, and possibly being initiated by pluripotency factors. Finally, we could show that mega-domains and TADs correspond to two different levels of three-dimensional genome organization superimposed on the Xi, independent of gene expression. We conclude that gene expression and chromatin accessibility during X-reactivation share similar kinetics, while genome organization might follow distinct principles.