What is the Difference Between Frog and Chick Gastrulation?

The process of gastrulation is a crucial stage in embryonic development, during which the single-layered blastula develops into a multilayered gastrula. The main differences between frog and chick gastrulation are as follows:

1. Initiation: Frog gastrulation starts with epiboly, while chick gastrulation starts through blastoderm.
2. Neural Tube Development: In frog embryos, the neural tube develops from the ectoderm, but in chick embryos, it develops from the mesoderm.
3. Cell Migration: The distinction in neural tube development is attributable to the dissimilar patterns of cell migration that take place during neurulation in the two species.
4. Cellular Rearrangement: Chick gastrulation involves a unique cellular rearrangement at the thickening of the tissue, with the cells of Hensen's node elongating across the blastula and later regressing to form the central nervous system.
5. Blastula: In frog gastrulation, the blastula is filled with yolk cells, making it more complicated than in chick gastrulation.

Despite these differences, the fate of the three germ layers (ectoderm, endoderm, and mesoderm) is the same in both frog and chick gastrulation.

Comparative Table: Frog vs Chick Gastrulation

The main differences between frog and chick gastrulation are as follows:

Understanding these differences is essential for studying embryonic development in these two species.