The
Drosophila embryonic protein SNAI1, commonly known as Snail, is a
zinc finger transcriptional repressor which downregulates the expression of
ectodermal genes within the
mesoderm. The nuclear protein encoded by this gene is structurally similar to the
Drosophila Snail protein, and is also thought to be critical for mesoderm formation in the developing embryo. At least two variants of a similar processed pseudogene have been found on chromosome 2. and represses the expression of the adhesion molecule, which induces the tightly bound epithelial cells to break loose from each other and migrate into the developing embryo to become mesenchymal cells. This process allows for the formation of the mesodermal layer in the developing embryo. Though SNAI1 is shown to repress expression of E-cadherin in epithelial cells, studies have shown homozygous mutant embryos are still able to form a mesodermal layer. However, the mesodermal layer present shows characteristics of epithelial cells and not mesenchymal cells (the mutant mesoderm cells exhibited a polarized state). Other studies show that mutation of specific ZFs contribute to a decrease in SNAI1 E-cadherin repression. Prostaglandin E2 (PE2), an important hormone in homeostasis and maintaining normal fertility and pregnancy, stabilizes SNAI1 post-transcriptionally and, therefore, also plays a role in embryogenesis. When the prostaglandin signaling pathway is compromised, SNAI1 transcriptional repressor activity decreases, increasing E-cadherin protein levels during gastrulation. However, this does not prevent gastrulation from occurring. == Clinical significance ==