Activin signalling and response to a morphogen gradient.
Using combinations of amphibian embryo tissues, it is shown that the selection of genes expressed by a cell is determined by its distance from a source of activin, a peptide growth factor contained in vegetal cells and able to induce other cells to form mesoderm. This long-range signal spreads over at least 10 cell diameters in a few hours. It does so by passive diffusion, because it can by-pass cells that do not themselves respond to the signal nor synthesize protein. These results provide direct support for the operation of a morphogen concentration gradient in vertebrate development.
Gurdon
J B
JB
Wellcome CRC Institute, Cambridge, UK.
Harger
P
P
Mitchell
A
A
Lemaire
P
P
D028341:Activins; D000818:Animals; D002455:Cell Division; D002465:Cell Movement; D046508:Culture Techniques; D004268:DNA-Binding Proteins / Q000235:genetics; D004058:Diffusion; D004625:Embryo, Nonmammalian / Q000502:physiology; D047108:Embryonic Development; D004627:Embryonic Induction; D005326:Fetal Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; D007265:Inhibins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins; D015398:Signal Transduction; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D014981:Xenopus; D000098908:Brachyury Protein
D028341:Activins; D004268:DNA-Binding Proteins; D005326:Fetal Proteins; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; D007265:Inhibins; D012333:RNA, Messenger; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D000098908:Brachyury Protein