Genomic organization, expression, and chromosome location of the human SNAIL gene (SNAI1) and a related processed pseudogene (SNAI1P)

Some of the zinc finger proteins of the snail family are essential in the formation of mesoderm during gastrulation and the development of neural crest and its derivatives. We have isolated the human SNAIL gene (HGMW- approved symbol SNAI1) and describe its genomic organization, having sequenced a region spanning more than 5882 bp. The human SNAIL gene contains three exons. The SNAIL transcript is 2.0 kb and is found in placenta and adult heart, lung, brain, liver, and skeletal muscle. It codes for a protein of 264 amino acids and 29.1 kDa. This protein contains three classic zinc fingers and one atypical zinc finger. The human SNAIL protein is 87.5, 58.7, 50.9, 50.7, 55.4, and 31.5% identical to mouse Snail, chicken snail-like, zebrafish snail1, zebrafish snail2, Xenopus snail, and Drosophila snail proteins, respectively. The zinc finger region is 95.5% identical between human and mouse Snail. Because Drosophila snail and twist are important regulators during mesoderm development and because human TWIST mutations have been implicated in craniosynostosis, a cohort of 59 patients with craniosynostosis syndromes were screened for SNAIL mutations. None were found. By somatic cell and radiation hybrid mapping panels, SNAIL was localized to human chromosome 20q13.2, between markers D20S886 and D20S109. A SNAIL-related, putative processed pseudogene (HGMW-approved symbol SNAI1P) was also isolated and maps to human chromosome 2q33-q37.