Short-range signaling by candidate morphogens of the TGF beta family and evidence for a relay mechanism of induction.
The specification and patterning of cell fates by a morphogen gradient is a unifying theme of developmental biology, yet little evidence exists for the presence of gradients in vivo or to show how such putative gradients form. Vg1 and activin are candidate morphogens involved in Xenopus mesoderm induction. This study suggests that these TGF beta family members act on adjacent cells but do not travel through the intact extracellular space to induce distant cells directly. Moreover, we present evidence for the presence of secondary inducing signals that could be involved in relaying signals to distant cells. These results suggest that if a localized cellular source of an inducer acts to pattern mesodermal cells at a distance in Xenopus embryos, it does so by a relay mechanism.
Reilly
K M
KM
Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Harvard University Cambridge, Massachusetts 02138, USA.
Melton
D A
DA
D028341:Activins; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002450:Cell Communication; D004058:Diffusion; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004627:Embryonic Induction / Q000502:physiology*; D005110:Extracellular Space / Q000378:metabolism; D006023:Glycoproteins / Q000235:genetics / Q000502:physiology*; D007265:Inhibins / Q000235:genetics / Q000502:physiology*; D008648:Mesoderm; D008969:Molecular Sequence Data; D009132:Muscles / Q000196:embryology; D012333:RNA, Messenger / Q000378:metabolism / Q000494:pharmacology; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D014981:Xenopus / Q000196:embryology; D029867:Xenopus Proteins
C513103:GDF1 protein, Xenopus; D006023:Glycoproteins; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D028341:Activins; D007265:Inhibins