Abstract

ACOSTA LOBO, Mariano Eliécer; VASQUEZ ARAQUE, Neil Aldrin  and  LONDONO FRANCO, Luis Fernando. X chromosome inactivation in mammalian embryonic development. Ces. Med. Vet. Zootec. [online]. 2013, vol.8, n.2, pp.108-119. ISSN 1900-9607.

Abstract The gene expression regulation during embryonic development early requires multiple and ordered epigenetic processes that ensure a correct differentiation and cellular proliferation. The inactivation of the X chromosome is a multiepigenetic process closely linked to embryonic development, involving the transcriptional silencing of one of the two X chromosomes in mammalian females cells. The best studied embryonic model is the mouse, where inactivation and reactivation cycles are observed during the formation of the trophoectoderm and the epiblast. The trophoectoderm and primitive endoderm shows a preferential inactivation by the paternal X, while the mass cell internal observed one random inactivation, and can inactivate both the paternal and the maternal X chromosome. X chromosome inactivation is also observed in male meiosis, showing silencing of the X chromosome, which lasts until fertilization. Here we review the molecular events in the progression of inactivation, from gametogenesis to the blastocyst, and the characteristics that regulate the processes of inactivation and reactivation of the X chromosome in female mammalian embryos.

Keywords : embryonic development; epigenetics; inactivation; X chromosome.

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