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ZFIN ID: ZDB-PUB-170323-21
Imaging early embryonic calcium activity with GCaMP6s transgenic zebrafish
Chen, J., Xia, L., Bruchas, M.R., Solnica-Krezel, L.
Date: 2017
Source: Developmental Biology   430(2): 385-396 (Journal)
Registered Authors: Chen, Jiakun, Solnica-Krezel, Lilianna
Keywords: Nodal, calcium transients, dorsal forerunner cells, embryonic cleavages, gastrulation, β-catenin
MeSH Terms:
  • Actins/genetics
  • Animals
  • Animals, Genetically Modified
  • Blastomeres/chemistry
  • Blastomeres/metabolism*
  • Blastomeres/ultrastructure
  • Blastula/chemistry
  • Blastula/ultrastructure
  • Body Patterning
  • Calcium/analysis*
  • Calcium Signaling/physiology*
  • Calmodulin/genetics
  • Embryo, Nonmammalian/chemistry
  • Embryo, Nonmammalian/metabolism
  • Embryo, Nonmammalian/ultrastructure
  • Genes, Reporter
  • Green Fluorescent Proteins/analysis
  • Green Fluorescent Proteins/genetics
  • Peptide Fragments/genetics
  • Peptides/genetics
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins/analysis*
  • Recombinant Fusion Proteins/genetics
  • Recombinant Fusion Proteins/metabolism
  • Ubiquitin/genetics
  • Zebrafish/embryology*
PubMed: 28322738 Full text @ Dev. Biol.
Intracellular Ca2+ signaling regulates cellular activities during embryogenesis and in adult organisms. We generated stable Tg[βactin2:GCaMP6s]stl351 and Tg[ubi:GCaMP6s]stl352 transgenic lines that combine the ubiquitously-expressed Ca2+ indicator GCaMP6s with the transparent characteristics of zebrafish embryos to achieve superior in vivo Ca2+ imaging. Using the Tg[βactin2:GCaMP6s]stl351 line featuring strong GCaMP6s expression from cleavage through gastrula stages, we detected higher frequency of Ca2+ transients in the superficial blastomeres during the blastula stages preceding the midblastula transition. Additionally, GCaMP6s also revealed that dorsal-biased Ca2+ signaling that follows the midblastula transition persisted longer during gastrulation, compared with earlier studies. We observed that dorsal-biased Ca2+ signaling is diminished in ventralized ichabod/β-catenin2 mutant embryos and ectopically induced in embryos dorsalized by excess β-catenin. During gastrulation, we directly visualized Ca2+ signaling in the dorsal forerunner cells, which form in a Nodal signaling dependent manner and later give rise to the laterality organ. We found that excess Nodal increases the number and the duration of Ca2+ transients specifically in the dorsal forerunner cells. The GCaMP6s transgenic lines described here enable unprecedented visualization of dynamic Ca2+ events from embryogenesis through adulthood, augmenting the zebrafish toolbox.