title: Visualization of the spatial arrangement of nuclear organization using three-dimensional fluorescence in situ hybridization in early mouse embryos: A new "EASI-FISH chamber glass" for mammalian embryos.
abstract: The fertilized oocyte begins cleavage, leading to zygotic gene activation (ZGA), which re-activates the resting genome to acquire totipotency. In this process, genomic function is regulated by the dynamic structural conversion in the nucleus. Indeed, a considerable number of genes that are essential for embryonic development are located near the pericentromeric regions, wherein the heterochromatin is formed. These genes are repressed transcriptionally in somatic cells. Three-dimensional fluorescence in situ hybridization (3D-FISH) enables the visualization of the intranuclear spatial arrangement, such as gene loci, chromosomal domains, and chromosome territories (CTs). However, the 3D-FISH approach in mammalian embryos has been limited to certain repeated sequences because of its unfavorable properties. In this study, we developed an easy-to-use chamber device (EASI-FISH chamber) for 3D-FISH in early embryos, and visualized, for the first time, the spatial arrangements of pericentromeric regions, the ZGA-activated gene (Zscan4) loci, and CTs (chromosome 7), simultaneously during the early cleavage stage of mouse embryos by 3D-FISH. As a result, it was revealed that morphological changes of the pericentromeric regions and CTs, and relocation of the Zscan4 loci in CTs, occurred in the 1- to 4-cell stage embryos, which was different from those in somatic cells. This convenient and reproducible 3D-FISH technique for mammalian embryos represents a valuable tool that will provide insights into the nuclear dynamics of development.
authors.affiliation: Graduate School of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Nakaya
authors.affiliation: Department of Evolutionary Studies of Biosystems, School of Advanced Sciences, SOKENDAI (The Graduate University for Advanced Studies), Kanagawa 240-0193, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tanabe
authors.affiliation: Department of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Takamatsu
authors.affiliation: Department of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan.
authors.forename: Misaki
authors.initials: M
authors.lastname: Hosokawa
authors.affiliation: Graduate School of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan.|Institute of Advanced Technology, Kindai University, Wakayama 642-0017, Japan.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Mitani
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics*; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D051379:Mice; D011247:Pregnancy
keywords: Chromosome territory; Gene locus; Pericentromeric region; Three-dimensional fluorescence in situ hybridization (3D-FISH)