Dynamic changes in H1 subtype composition during epigenetic reprogramming

• Published in: The Journal of cell biology Vol. 216; no. 10; pp. 3017 - 3028
• Main Authors: Izzo, Annalisa, Ziegler-Birling, Céline, Hill, Peter W S, Brondani, Lydia, Hajkova, Petra, Torres-Padilla, Maria-Elena, Schneider, Robert
• Format: Journal Article
• Language: English
• Published: United States Rockefeller University Press 02.10.2017; The Rockefeller University Press
• Subjects: Cells; Cellular Biology; Chromatin; Chromatin remodeling; Developmental stages; Embryos; Gene expression; Germ cells; Histone H1; Life Sciences; Localization; Proteins; Relative abundance; Replication; Sex differentiation; Somatic cells
• ISSN: 0021-9525; 1540-8140; 1540-8140
• DOI: 10.1083/jcb.201611012

In mammals, histone H1 consists of a family of related proteins, including five replication-dependent (H1.1-H1.5) and two replication-independent (H1.10 and H1.0) subtypes, all expressed in somatic cells. To systematically study the expression and function of H1 subtypes, we generated knockin mouse lines in which endogenous H1 subtypes are tagged. We focused on key developmental periods when epigenetic reprogramming occurs: early mouse embryos and primordial germ cell development. We found that dynamic changes in H1 subtype expression and localization are tightly linked with chromatin remodeling and might be crucial for transitions in chromatin structure during reprogramming. Although all somatic H1 subtypes are present in the blastocyst, each stage of preimplantation development is characterized by a different combination of H1 subtypes. Similarly, the relative abundance of somatic H1 subtypes can distinguish male and female chromatin upon sex differentiation in developing germ cells. Overall, our data provide new insights into the chromatin changes underlying epigenetic reprogramming. We suggest that distinct H1 subtypes may mediate the extensive chromatin remodeling occurring during epigenetic reprogramming and that they may be key players in the acquisition of cellular totipotency and the establishment of specific cellular states.