title: Predictability of dorso-ventral asymmetry in the cleavage stage zebrafish embryo: an analysis using lithium sensitivity as a dorso-ventral marker.
abstract: The dorso-ventral axis in zebrafish first becomes apparent at gastrulation, when the future ventral side appears thinner than the dorsal side. The exact time of establishment of the dorso-ventral axis is not known. We show here that the dorso-ventral axis is specified as early as the 32 cell stage. Using lithium as a marker for dorso-ventral asymmetry, we show that lithium-sensitivity is a characteristic of future ventral cell, but not future dorsal cells, and that there is an asymmetric lithium-sensitivity along the long axis of the 32 cell stage embryo. Consequently, the dorso-ventral axis corresponds to the long axis of the embryo. Because the effect of lithium treatment is short-lived, the dorso-ventral axis must be specified in zebrafish already at the 32 cell stage.
authors.affiliation: Department of Physiological Sciences, The Medical School, University of Newcastle-upon-Tyne, UK. aanstad@mpimg-berlin-dahlem.mpg.de
authors.forename: P
authors.initials: P
authors.lastname: Aanstad
authors.forename: M
authors.initials: M
authors.lastname: Whitaker
mesh_terms: D000818:Animals; D015415:Biomarkers; D001757:Blastomeres; D019521:Body Patterning / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D004627:Embryonic Induction; D005456:Fluorescent Dyes / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology*; D008845:Microinjections; D009930:Organic Chemicals; D015027:Zebrafish / Q000196:embryology*
chemical_list: D015415:Biomarkers; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C071336:calcium green; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D008094:Lithium