Chromatin in early mammalian embryos : achieving the pluripotent state
Fulka, Helena, St. John, Justin C., Fulka, Josef and Hozak, Pavel (2008) Chromatin in early mammalian embryos : achieving the pluripotent state. Differentiation, Vol.76 (No.1). pp. 3-14. ISSN 0301-4681Full text not available from this repository.
Official URL: http://dx.doi.org/10.1111/j.1432-0436.2007.00247.x
Gametes of both sexes (sperm and oocyte) are highly specialized and differentiated but within a very short time period post-fertilization the embryonic genome, produced by the combination of the two highly specialized parental genomes, is completely converted into a totipotent state. As a result, the one-cell-stage embryo can give rise to all cell types of all three embryonic layers, including the gametes. Thus, it is evident that extensive and efficient reprogramming steps occur soon after fertilization and also probably during early embryogenesis to reverse completely the differentiated state of the gamete and to achieve toti- or later on pluripotency of embryonic cells. However, after the embryo reaches the blastocyst stage, the first two distinct cell lineages can be clearly distinguished-the trophectoderm and the inner cells mass. The de-differentiation of gametes after fertilization, as well as the differentiation that is associated with the formation of blastocysts, are accompanied by changes in the state and properties of chromatin in individual embryonic nuclei at both the whole genome level as well as at the level of individual genes. In this contribution, we focus mainly on those events that take place soon after fertilization and during early embryogenesis in mammals. We will discuss the changes in DNA methylation and covalent histone modifications that were shown to be highly dynamic during this period; moreover, it has also been documented that abnormalities in these processes have a devastating impact on the developmental ability of embryos. Special attention will be paid to somatic cell nuclear transfer as it has been shown that the aberrant and inefficient reprogramming may be responsible for compromised development of cloned embryos.
|Item Type:||Journal Item|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Divisions:||Faculty of Medicine > Warwick Medical School|
|Library of Congress Subject Headings (LCSH):||Chromatin, Epigenetics, Somatic cells, Cell nuclei -- Transplantation, Mammals -- Embryology, Cloning|
|Journal or Publication Title:||Differentiation|
|Official Date:||January 2008|
|Number of Pages:||12|
|Page Range:||pp. 3-14|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||European Science Foundation (ESF), Grantová agentura České republiky [Czech Science Foundation] (GACR)|
|Grant number:||STE/05/E004 (ESF), 204/05/H023 (GACR)|
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