Eph signaling is required for segmentation and differentiation of the somites.
Somitogenesis involves the segmentation of the paraxial mesoderm into units along the anteroposterior axis. Here we show a role for Eph and ephrin signaling in the patterning of presomitic mesoderm and formation of the somites. Ephrin-A-L1 and ephrin-B2 are expressed in an iterative manner in the developing somites and presomitic mesoderm, as is the Eph receptor EphA4. We have examined the role of these proteins by injection of RNA, encoding dominant negative forms of Eph receptors and ephrins. Interruption of Eph signaling leads to abnormal somite boundary formation and reduced or disturbed myoD expression in the myotome. Disruption of Eph family signaling delays the normal down-regulation of her1 and Delta D expression in the anterior presomitic mesoderm and disrupts myogenic differentiation. We suggest that Eph signaling has a key role in the translation of the patterning of presomitic mesoderm into somites.
Department of Anatomy and Developmental Biology, University College, London, WC1E 6BT, UK.
L
L
Durbin
C
C
Brennan
K
K
Shiomi
J
J
Cooke
A
A
Barrios
S
S
Shanmugalingam
B
B
Guthrie
R
R
Lindberg
N
N
Holder
D000595:Amino Acid Sequence; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation; D002970:Cleavage Stage, Ovum / Q000502:physiology*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D036386:Ephrin-A5; D036388:Ephrin-B2; D005326:Fetal Proteins / Q000235:genetics / Q000502:physiology*; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011485:Protein Binding; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D036121:Receptor, EphA3; D036122:Receptor, EphA4; D036224:Receptor, EphB4; D036081:Receptors, Eph Family; D015398:Signal Transduction; D019170:Somites / Q000502:physiology*; D014157:Transcription Factors; D015027:Zebrafish; D029961:Zebrafish Proteins
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D036386:Ephrin-A5; D036388:Ephrin-B2; D005326:Fetal Proteins; D008024:Ligands; D008565:Membrane Proteins; D009687:Nuclear Proteins; D020794:Receptor Protein-Tyrosine Kinases; D036121:Receptor, EphA3; D036122:Receptor, EphA4; D036224:Receptor, EphB4; D036081:Receptors, Eph Family; D014157:Transcription Factors; D029961:Zebrafish Proteins; C093234:Tcf15 protein, mouse; C512784:tcf15 protein, zebrafish