| We again imaged gastrulation in an albino Xenopus embryo. The field of view in this movie is 1 mm x 1 mm and the depth of the imaged volume is 0.65 mm. Highly scattering regions appear red, low scattering regions appear blue, and noisy areas appear black. This movie shows specifically the involuting mesoderm migrating up along the blastocoel roof, i.e., along the inner surface of the ectoderm. |