GSE123109
Single-cell three dimensional genome structures of rice egg, sperm, and unicellular zygote
Chromatin conformation capture assays, such as 3C and Hi-C, allow for studies of three-dimensional (3D) genome structures in bulk samples through proximity ligation of DNA. However, the difference between cells can only be observed by single-cell measurements that avoid ensemble averaging3, 4,5. To study 3D chromatin organization and dynamics before and after fertilization in flowering plants, we analyzed the 3D genomes of rice egg, sperm, and unicellular zygote as well as shoot cells. We show that chromatin architectures of rice egg and sperm are comparable to that of somatic cells and are reorganized after fertilization in unicellular zygote. The rice single cell 3D genomes display specific features of chromosome compartments and configuration of telomeres/centromeres compared to those shown in mammalian single cells. Active and silent chromatin domains gather to form multiple foci in the nuclear space. Notably, the 3D genomes of egg, unicellular zygote, and shoot cells contain a compact silent center (CSC), which is absent in sperm. CSC is dynamically reorganized after fertilization and is likely to be involved in gene regulation related to zygotic genome activation (ZGA). Our results reveal specific 3D genome features of plant gametes and unicellular zygote and provide a spatial chromatin basis for ZGA and gene expression in plant. Overall design: Single-cell Hi-C sequencing data of four eggs, four sperms, three unicellular zygotes, and two shoot cells