X chromosome status : a gatekeeper of germ cells meiotic entry

X chromosome reactivation in female mouse germ cells is essential for the transmission of one active X chromosome to the progeny. However, despite its key role in development, the mechanistic details and kinetics still remain elusive, as previous studies were restricted by a scarcity of cells in viv...

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Detalles Bibliográficos
Autor: Severino, Jacqueline
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/671536
Acceso en línea:http://hdl.handle.net/10803/671536
Access Level:acceso abierto
Palabra clave:Germline
X chromosome reactivation
Meiosis
Epigenetic reprogramming
Células madre
Línea germinal
Reactivación del cromosoma X
Reprogramación epigenética
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Descripción
Sumario:X chromosome reactivation in female mouse germ cells is essential for the transmission of one active X chromosome to the progeny. However, despite its key role in development, the mechanistic details and kinetics still remain elusive, as previous studies were restricted by a scarcity of cells in vivo and a lack of adequate in vitro systems. Here, I present the characterization of X-chromosome dynamics during germ cell formation, which was possible thanks to the development of a tailor-made in vitro system which allows the accurate profiling of X-chromosome activity. We recapitulate X-inactivation starting in epiblast-like cells (EpiLCs), progressing in primordial germ cell-like cells (PGCLCs), followed by X-reactivation in germ cells upon meiotic entry. We show that PGCLCs undergoing X-inactivation can enter meiosis more efficiently, while PGCLCs bypassing X-inactivation, with the consequent lack of X-reactivation, show a reduced meiotic potential. We conclude that tracing the X chromosome status during germ cell formation facilitates the dissection of the relationship between X chromosome dynamics and proper germline fate acquisition