St12-5.65hpf

mid gastrula, six-row neural plate stage (5.65 hours), the blastopore is still central and open. The neural plate is flat and constituted by six rows of 6 cells (3 rows of a-line cells and 3 rows of A-line cells) that form a characteristically regular structure.

Dorsal view of three-dimensional image (upper), 50% section image (middle), and longitudinal section image (lower). Dashed lines in middle indicate the position of the section. Scale bar = 50 micro m. b.p., blastopore; n.p., neural plate.