Year: 2014
Type: review
Abstract: The hourglass model of development postulates divergence in early and late embryo development bridged by a period of developmental constraint at mid-embryogenesis. Recently, molecular support for the hourglass model of development has accumulated, with the emphasis on studies using zebrafish and Drosophila species. Across mammals, the hourglass model and specifically divergence in early development has thus far received little attention. Divergence in mammalian pre-implantation development is particularly interesting because of its potential impact on derivation of pluripotent embryonic stem cells. Here, we review recent findings that support the hourglass model of development. We provide striking examples of variation in key events in mammalian peri-implantation development and their potential consequences for pluripotency of embryonic stem cell lines, including mechanisms of cell signalling and differentiation, gene regulatory networks, X-chromosome inactivation, and epigenetic regulation. The variation in these processes indicates divergence in early mammalian development as was postulated by the hourglass model of development. We discuss the naive and primed states of pluripotency in light of this developmental divergence and their implications for human pluripotent stem cell states.
DOI: 10.1111/brv.12117
Authors: Ewart Kuijk, Niels Geijsen, Edwin Cuppen
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W1959090076