title: Mesodermal induction in early amphibian embryos by activin A (erythroid differentiation factor).
abstract: Recently the mesoderm-inducing effects of the transforming growth factor β (TGF-β) family of proteins have been widely examined. In an attemt to elucidate the functions of these proteins, porcine inhibin A and activin A (erythroid differentiation factor; EDF) were examined. Treatment of explants with activin A led to differentiation of mesodermal derivatives such as mesenchyme, notochord, blood cells and muscle, but inhibin A had a much lesser effect. The mesodermal differentiation induced by activin A was also comfirmed by analyses using a polyclonal antibody against muscle myosin. By indirect immunofluorescence analysis, the differentiation of muscle blocks was observed in the activin-A-treated explants, whereas no differentiation was observed in inhibin-A-treated and control explants. These findings confirm that this protein of the TGF-β family has mesoderm-inducing ability.
authors.affiliation: Department of Biology, Yokohama City University, 22-2 Seto, Kanazawa-ku, 236, Yokohama, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
authors.affiliation: Department of Biology, Yokohama City University, 22-2 Seto, Kanazawa-ku, 236, Yokohama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakano
authors.affiliation: Department of Biology, Yokohama City University, 22-2 Seto, Kanazawa-ku, 236, Yokohama, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Biological Laboratory, Nippon Medical School, 2-297-2 Kosugi, Nakahara-ku, 211, Kawasaki, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Kinoshita
authors.affiliation: Central Research Laboratories, Ajinomoto Co. Inc., 1-1 Suzuki, Kawasaki-ku, 210, Kawasaki, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Central Research Laboratories, Ajinomoto Co. Inc., 1-1 Suzuki, Kawasaki-ku, 210, Kawasaki, Japan.
authors.forename: Hiroshiro
authors.initials: H
authors.lastname: Shibai
authors.affiliation: Institute of Applied Biochemistry, Tsukuba University, Tennodai, Tsukuba, 305, Ibaraki, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Ueno
keywords: Activin A; Erythroid differentiation factor; Mesoderm induction; Xenopus laevis