title: Formation of mesodermal pattern by secondary inducing interactions.
abstract: A highly purified vegetalizing factor induces endoderm preferentially in amphibian gastrula ectoderm. After combination of this factor with less pure fractions, a high percentage of trunks and tails with notochord and somites are induced. The induction of these mesodermal tissues depends on secondary factors which may act on plasma membrane receptors of the target cells. The secondary factors are probably proteins as they are inactivated by trypsin or cellulose-bound proteinase K. They are not inactivated by thioglycolic acid.The implication of these findings for tissue determination and differentiation in normal development in relation to the anlageplan for endoderm and mesodermal tissues is discussed.
authors.affiliation: Institut für Molekularbiologie und Biochemie, Freie Universität, Berlin, Arnimallee 22, D-1000, Berlin 33.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Asahi
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: 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: Amphibia; Mesoderm formation; Secondary factors