title: Live imaging of whole mouse embryos during gastrulation: migration analyses of epiblast and mesodermal cells.
abstract: During gastrulation in the mouse embryo, dynamic cell movements including epiblast invagination and mesodermal layer expansion lead to the establishment of the three-layered body plan. The precise details of these movements, however, are sometimes elusive, because of the limitations in live imaging. To overcome this problem, we developed techniques to enable observation of living mouse embryos with digital scanned light sheet microscope (DSLM). The achieved deep and high time-resolution images of GFP-expressing nuclei and following 3D tracking analysis revealed the following findings: (i) Interkinetic nuclear migration (INM) occurs in the epiblast at embryonic day (E)6 and 6.5. (ii) INM-like migration occurs in the E5.5 embryo, when the epiblast is a monolayer and not yet pseudostratified. (iii) Primary driving force for INM at E6.5 is not pressure from neighboring nuclei. (iv) Mesodermal cells migrate not as a sheet but as individual cells without coordination.
authors.affiliation: Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Okazaki Aichi, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nakazato
authors.forename: Philipp J
authors.initials: PJ
authors.lastname: Keller
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kajiura-Kobayashi
authors.forename: Ernst H K
authors.initials: EH
authors.lastname: Stelzer
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mochizuki
authors.forename: Shigenori
authors.initials: S
authors.lastname: Nonaka
mesh_terms: D000818:Animals; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D058948:Cell Tracking; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000166:cytology*; D054262:Gastrulation; D021621:Imaging, Three-Dimensional; D008648:Mesoderm / Q000166:cytology* / Q000378:metabolism; D051379:Mice