title: Characterisation of two snail genes in the gastropod mollusc Patella vulgata. Implications for understanding the ancestral function of the snail-related genes in Bilateria.
abstract: Snail genes have been found to play a role in mesoderm formation in two of the three clades of bilaterians, deuterostomes (comprising the chordates) and ecdysozoans (comprising the arthropods). No clear data are available on the role these genes play in development of the mesoderm in the third clade, that of lophotrochozoans (comprising annelids and molluscs). We identified two new members of the snail gene family in the gastropod mollusc Patella vulgata. Phylogenetic analysis showed that the two genes clearly belong to the snail sub-family. Their expression patterns do not indicate a role during early mesoderm formation. In fact, contrary to expectations, the snail genes of Patella were mostly expressed in the ectoderm. In view of the location of their expression sites, we suggest that these genes could be involved in regulating epithelial-mesenchymal transitions (EMT) and cell motility, as has recently been demonstrated for snail genes in vertebrates. This may well correspond to the ancestral function of these genes. The results are discussed in the light of the evolutionary origin of the mesoderm. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00427-002-0228-1.
authors.affiliation: Centre de Génétique Moléculaire, CNRS UPR 2167, 91198 Gif-sur-Yvette, France. lespinet@ncbi.nlm.nih.gov
authors.forename: Olivier
authors.initials: O
authors.lastname: Lespinet
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Nederbragt
authors.forename: Michel
authors.initials: M
authors.lastname: Cassan
authors.forename: Wim J A G
authors.initials: WJ
authors.lastname: Dictus
authors.forename: André E
authors.initials: AE
authors.lastname: van Loon
authors.forename: André
authors.initials: A
authors.lastname: Adoutte
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D002454:Cell Differentiation / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D005810:Multigene Family; D009474:Neurons / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D000071250:Snail Family Transcription Factors; D012908:Snails / Q000196:embryology / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors