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Cohesin Smc1β determines meiotic chromatin axis loop organization

Meiotic chromosomes consist of proteinaceous axial structures from which chromatin loops emerge. Although we know that loop density along the meiotic chromosome axis is conserved in organisms with different genome sizes, the basis for the regular spacing of chromatin loops and their organization is...

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Detalles Bibliográficos
Autores principales: Novak, Ivana, Wang, Hong, Revenkova, Ekaterina, Jessberger, Rolf, Scherthan, Harry, Höög, Christer
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213612/
https://www.ncbi.nlm.nih.gov/pubmed/18180366
http://dx.doi.org/10.1083/jcb.200706136
Descripción
Sumario:Meiotic chromosomes consist of proteinaceous axial structures from which chromatin loops emerge. Although we know that loop density along the meiotic chromosome axis is conserved in organisms with different genome sizes, the basis for the regular spacing of chromatin loops and their organization is largely unknown. We use two mouse model systems in which the postreplicative meiotic chromosome axes in the mutant oocytes are either longer or shorter than in wild-type oocytes. We observe a strict correlation between chromosome axis extension and a general and reciprocal shortening of chromatin loop size. However, in oocytes with a shorter chromosome axis, only a subset of the chromatin loops is extended. We find that the changes in chromatin loop size observed in oocytes with shorter or longer chromosome axes depend on the structural maintenance of chromosomes 1β (Smc1β), a mammalian chromosome–associated meiosis-specific cohesin. Our results suggest that in addition to its role in sister chromatid cohesion, Smc1β determines meiotic chromatin loop organization.