Insights & Perspectives
The “occlusis” model of cell fate restriction
Version of Record online: 15 OCT 2010
Copyright © 2011 WILEY Periodicals, Inc.
Volume 33, Issue 1, pages 13–20, January 2011
How to Cite
Lahn, B. T. (2011), The “occlusis” model of cell fate restriction. Bioessays, 33: 13–20. doi: 10.1002/bies.201000090
- Issue online: 14 DEC 2010
- Version of Record online: 15 OCT 2010
- cell fate restriction;
A simple model, termed “occlusis”, is presented here to account for both cell fate restriction during somatic development and reestablishment of pluripotency during reproduction. The model makes three assertions: (1) A gene's transcriptional potential can assume one of two states: the “competent” state, wherein the gene is responsive to, and can be activated by, trans-acting factors in the cellular milieu, and the “occluded” state, wherein the gene is blocked by cis-acting, chromatin-based mechanisms from responding to trans-acting factors such that it remains silent irrespective of whether transcriptional activators are present in the milieu. (2) As differentiation proceeds in somatic lineages, lineage-inappropriate genes shift progressively and irreversibly from competent to occluded state, thereby leading to the restriction of cell fate. (3) During reproduction, global deocclusion takes place in the germline and/or early zygotic cells to reset the genome to the competent state in order to facilitate a new round of organismal development.