Teeth are one of the most fascinating innovations of vertebrates. Their diversity of shape, size, location, and number in vertebrates is astonishing. If the molecular mechanisms underlying the morphogenesis of individual teeth are now relatively well understood, thanks to the detailed experimental work that has been performed in model organisms (mainly mouse and zebrafish), the mechanisms that control the organization of the dentition are still a mystery. Mammals display simplified dentitions when compared to other vertebrates with only a single tooth (...) row positioned in the anterior part of the mouth, whereas other vertebrates exhibit tooth rows in many locations. As proposed 60 years ago, tooth rows can be formed sequentially from an initiator tooth. Recent results in zebrafish have now largely confirmed this hypothesis. Here this observation is generalized upon and it is suggested that in most vertebrates tooth rows could form sequentially from a single initiator tooth. (shrink)

In the genomics era, bioinformatic analysis, especially in non‐model species, facilitates the identification and naming of numerous new proteins, the function of which is then inferred through homology searches. Here, we question certain aspects of these approaches. What are the criteria that permit such a determination? What are their limits? Naming is classifying. We review the different criteria that are used to name a protein and discuss their constraints. We observe that the name given to a protein often introduces a (...) bias for further functional analyses, a bias that is not often taken into account when analysing results. Last but not least, the heterogeneity of criteria used for naming proteins leads to self‐inconsistent or contradictory protein classification that is potentially misleading. Finally, we recommend a wider use of phylogenetic criteria in protein naming. BioEssays 30:349–357, 2008. © 2008 Wiley Periodicals, Inc. (shrink)