3D Chromatin Structures of Mature Gametes and Structural Reprogramming during Mammalian Embryogenesis

Publication date: 13 July 2017
Source:Cell, Volume 170, Issue 2
Author(s): Yuwen Ke, Yanan Xu, Xuepeng Chen, Songjie Feng, Zhenbo Liu, Yaoyu Sun, Xuelong Yao, Fangzhen Li, Wei Zhu, Lei Gao, Haojie Chen, Zhenhai Du, Wei Xie, Xiaocui Xu, Xingxu Huang, Jiang Liu
High-order chromatin structure plays important roles in gene expression regulation. Knowledge of the dynamics of 3D chromatin structures during mammalian embryo development remains limited. We report the 3D chromatin architecture of mouse gametes and early embryos using an optimized Hi-C method with low-cell samples. We find that mature oocytes at the metaphase II stage do not have topologically associated domains (TADs). In sperm, extra-long-range interactions (>4 Mb) and interchromosomal interactions occur frequently. The high-order structures of both the paternal and maternal genomes in zygotes and two-cell embryos are obscure but are gradually re-established through development. The establishment of the TAD structure requires DNA replication but not zygotic genome activation. Furthermore, unmethylated CpGs are enriched in A compartment, and methylation levels are decreased to a greater extent in A compartment than in B compartment in embryos. In summary, the global reprogramming of chromatin architecture occurs during early mammalian development.

Graphical abstract

Teaser

A comparative resource lays out the distinct conformational chromatin dynamics for mammalian sperm, oocytes, and early embryos.


from # All Medicine by Alexandros G. Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2upAJpY
via IFTTT