Fig. S7

Behavior of Ttrap^MO cells in maternal-zygotic one-eyed pinhead (MZoep) embryos. A total of 23 MZoep embryos were transplanted with a mix of wild-type and Ttrap^MO cells. Wild-type embryos were pre-labeled at the one-cell stage with either Alexa Fluor 568 dye (red fluorescence; Invitrogen), or with fluorescein-labeled Ttrap MO (green fluorescence; Genetools). In all 23 cases, Ttrap^MO cells failed to internalize. Left panels (bright field), middle panels (rhodamine filter), right panels (GFP filter). Time-course begins approximately at germ ring to shield stage (5.5 to 6 hpf), and ends at around late tailbud to 1- to 3-somite stage (10.5 to 11 hpf). (A,B) Representative time-lapse images of wild-type vs Ttrap^MO cell migration in an MZoep background. Green arrows indicate wild-type cells in region of endodermal progenitors and in a deeper cell layer and are therefore in a different focal plane, hence becoming more and more out of focus over the course of the time-lapse study. Red arrows indicate Ttrap^MO cells, which, like MZoep (or oep) cells fail to involute and remain at the surface, accumulating at the vegetal-dorsal thickening (black arrow), but not in the neighboring endodermal progenitor regions. All embryos oriented with dorsal side to the right. MZoep embryos were obtained from a homozygous cross of parental fish generated from an oep ^t₃⁵⁷/ ^t₃⁵⁷ incross followed by cripto rescue. Digital images were captured using the Lumar V12 and AxioCam MRc5 and the images processed using Axiovision 4.5 Software (Zeiss). Cell transplantations were carried out using a Cell Tram Vario (Eppendorf).