title: A mesoderm-inducing factor from a Xenopus laevis cell line : Chemical properties and relation to the vegetalizing factor from chicken embryos.
abstract: We have compared the chemical properties and biological activities of the mesoderm-inducing factor that is secreted by the Xenopus XTC cell line with the vegetalizing factor from chicken embryos. The inducing activity of the factors was tested in different concentrations on totipotent ectoderm either by implantation into early gastrulae of Triturm alpestris or by application of solutions to isolated ectoderm of early gastrulae of Xenopus laevis. Both factors have similar properties. They are not irreversibly inactivated after treatment with 6 M urea or with phenol at 60° C. Reduction with thioglycolic acid inactivates the factors completely. The inducing activity of XTC-conditioned medium decreases only slightly after treatment with 50% formic acid. The apparent molecular mass and the isoelectric point of the factors are similar. The XTC factor was partially purified by size-exclusion and reversed-phase high-pressure liquid chromatography and by isoelectric focusing. The possible relationship of these factors to transforming growth factor β is discussed.
authors.affiliation: Abteilung für Zoophysiologie Universität-GHS-Essen, Universitätsstraße 5, D-4300, Essen 1, Germany.
authors.forename: Horst
authors.initials: H
authors.lastname: Grunz
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Jochen
authors.initials: J
authors.lastname: Born
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Michael
authors.initials: M
authors.lastname: Davids
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Peter
authors.initials: P
authors.lastname: Hoppe
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Beate
authors.initials: B
authors.lastname: Loppnow-Blinde
authors.affiliation: Abteilung für Zoophysiologie Universität-GHS-Essen, Universitätsstraße 5, D-4300, Essen 1, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Tacke
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Heinz
authors.initials: H
authors.lastname: Tiedemann
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Hildegard
authors.initials: H
authors.lastname: Tiedemann
keywords: Chicken vegetalizing factor; Mesoderm induction; Xenopus XTC factor