Figure 1.

Zebrafish Germ Layer Progenitor Cells Exhibit Distinct Cell Migration Modes In Vitro

(A) Bright-field (BF) and fluorescence images of blebbing progenitor cells cultured in serum-free medium in confinement with GPI-RFP (membrane, red) and Lifeact-GFP (cortex, green). Red arrow marks cellular bleb. Scale bar represents 20 μm.

(A′) BF time-lapse images of non-motile progenitor cells related to culture conditions in (A). Blue asterisk indicates cell center. Scale bar represents 20 μm.

(B) TIRFM images of Lifeact-GFP in mesendodermal progenitors cultured on 2D substrates. Arrows mark filopodia (yellow) and lamellipodia (white). Scale bar represents 10 μm.

(B′) BF time-lapse images related to culture conditions in (B). Orange asterisks indicate exemplary migrating cells. Scale bar represents 20 μm.

(B″) Representative tracks of motile mesendodermal cells over 20 min (time lag 30 s, n = 15 cells).

(C) BF and fluorescence images of polarized progenitor cells with GPI-RFP (red) and Lifeact-GFP (green) cultured in 20% serum in confinement. Yellow arrow points at the bleb-like protrusion front. Scale bar represents 20 μm.

(C′) BF time-lapse images of motile stable-bleb cells cultured as described in (C). Red asterisk indicates cell movement. Scale bar represents 20 μm.

(D and D′) Sketch and BF images summarizing different migration phenotypes of embryonic progenitor cells in vitro. All progenitor cells were obtained from embryos at sphere stage and cultured on Fibronectin-coated substrates. Scale bar represents 20 μm.

See also Movie S1 and Extended Experimental Procedures.