31. In the absence of these signals, ectoderm reverts to its default state of neural tissue. 32. Sox2 inhibits differentiation into the mesendoderm germ layer and promotes differentiation into neural ectoderm germ layer. 33. The cellular tissues that ultimately become teeth originate from the embryonic germ layer, the ectoderm . 34. The tentacles bear stinging nematocytes on the outer half of the ectoderm ( outside layer ). 35. These cells are in contact with the outer ectoderm cells, which will eventually become the lens. 36. During development, definitive endoderm and ectoderm differentiates into several gastrointestinal epithelial lineages, including endocrine cells. 37. One group of cells fated to become melanocytes migrates dorsolaterally into the ectoderm towards the ventral midline. 38. By the upward growth of the mesoderm the neural tube is ultimately separated from the overlying ectoderm . 39. These anomalies are thought to reflect changes in the brain as both are derived from the ectoderm . 40. The ectospermalege is derived from the ectoderm . into the groove, and pierce the pleural membrane.
