The molecular phylogeny of eph receptors and ephrin ligands
Date
2008-05-21
Authors
Mellott, Dan O
Burke, Robert D
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Background: The tissue distributions and functions of Eph receptors and their ephrin ligands have
been well studied, however less is known about their evolutionary history. We have undertaken a
phylogenetic analysis of Eph receptors and ephrins from a number of invertebrate and vertebrate
species.
Results: Our findings indicate that Eph receptors form three major clades: one comprised of nonchordate
and cephalochordate Eph receptors, a second comprised of urochordate Eph receptors,
and a third comprised of vertebrate Eph receptors. Ephrins, on the other hand, fall into either a
clade made up of the non-chordate and cephalochordate ephrins plus the urochordate and
vertebrate ephrin-Bs or a clade made up of the urochordate and vertebrate ephrin-As.
Conclusion: We have concluded that Eph receptors and ephrins diverged into A and B-types at
different points in their evolutionary history, such that primitive chordates likely possessed an
ancestral ephrin-A and an ancestral ephrin-B, but only a single Eph receptor. Furthermore, ephrin-
As appear to have arisen in the common ancestor of urochordates and vertebrates, whereas
ephrin-Bs have a more ancient bilaterian origin. Ancestral ephrin-B-like ligands had transmembrane
domains; as GPI anchors appear to have arisen or been lost at least 3 times.
Description
BioMed Central
Keywords
Citation
Mellott and Burke. The molecular phylogeny of eph receptors and ephrin ligands. BMC Cell Biology 2008, 9:27