Microsurgery: making an organotypic dorsal isolate from a late gastrula stage Xenopus laevis embryo.
Channel: Lance Davidson
Date: 2021-09-30

This video details microsurgical manipulations to isolate and visualize morphogenesis of dorsal tissues, a multilayer structure composed of neural ectoderm, mesoderm, and endoderm in the Xenopus embryo. The dorsal isolate is dissected from mid- to late-stage gastrula stage embryos after involution and archenteron formation. Germ-layer contacts between dorsal endoderm, mesoderm, and ectoderm generated by gastrulation movements are maintained in the dorsal isolate. If properly made, the dorsal isolate will undergo large-scale morphogenetic movements that parallel movement of the same tissues in vivo. Neural ectoderm in dorsal isolates can fold and fuse into a neural tube. Wide dorsal isolates may include epidermal progenitors resulting in formation of fin-like structures in equivalently aged isolates. This explant was used to describe cell behaviors in the notochord and paraxial mesoderm during axis elongation and segmentation. Tissue scale biomechanics and patterning processes that drive convergent extension at these later, post-involution stages and during segmentation can be studied within the dorsal isolate. Note: this video was made to accompany a more detailed protocol to be published by Cold Spring Harbor Laboratory Protocols in 2022. Copyright: Lance Davidson.