title: Activin can induce the formation of axial structures and is expressed in the hypoblast of the chick.
abstract: We show that PIF/activin can induce the formation of axial structures including a full-length notochord, segmented somites, and a neural tube in isolated epiblasts from chick blastulae. Using degenerate PCR primers, we have cloned a fragment of the activin beta B chain from chick hypoblast cDNA, and a fragment of the activin beta A chain from chick genomic DNA. Furthermore, we show that in the chick, activin is transcribed precisely when axial mesoderm is being induced. Since exogenous PIF/activin can induce the formation of axial structures and since activin beta B is transcribed at the time and place where the mesodermal axial structures are being induced, we propose that in the chick, activin B is the endogenous inducer of the body axis.
authors.affiliation: Department of Zoology, Hebrew University of Jerusalem, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Mitrani
authors.forename: T
authors.initials: T
authors.lastname: Ziv
authors.forename: G
authors.initials: G
authors.lastname: Thomsen
authors.forename: Y
authors.initials: Y
authors.lastname: Shimoni
authors.forename: D A
authors.initials: DA
authors.lastname: Melton
authors.forename: A
authors.initials: A
authors.lastname: Bril
mesh_terms: D028341:Activins; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D002642:Chick Embryo; D003001:Cloning, Molecular; D007265:Inhibins / Q000235:genetics / Q000502:physiology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009672:Notochord / Q000166:cytology / Q000502:physiology*; D015345:Oligonucleotide Probes
chemical_list: D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D028341:Activins; D007265:Inhibins