title: Vegetalising factor extracted from the fish swimbladder and tested on presumptive ectoderm ofTriturus embryos.
abstract: Vegetalising factor was isolated from swimbladder of crusian carp (Carassius auratus) by solubilishing with 8 M urea the precipitate obtained after digesting the swimbladder with collagenase. The urea-soluble fraction vegetalised isolated presumptive ectoderm ofTriturus gastrula and produced both undifferentiated mesodermal and endodermal cells. Brief heating of the fraction changed its capacity to produce organised mesodermal tissues, such as notochord and somite, and the frequency of induction of undifferentiated cells was reduced. By inserting the urea-soluble fraction into the blastocoel of an early gastrula, embryos without epidermis were obtained. Some of the embryos consisted of undifferentiated mesodermal and endodermal cells, but in the remaining ones small fragments of notochord, small numbers of somites and pronephros developed, enclosed by endodermal cells.
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Kawakami
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Noda
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kurihara
authors.affiliation: Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Okuma
keywords: Embryonic induction; Vegetalising factor