Presence of activin (erythroid differentiation factor) in unfertilized eggs and blastulae of Xenopus laevis.
Activin A, a member of the transforming growth factor beta superfamily, has recently been found to have potent mesoderm-inducing activity on isolated early Xenopus animal-cap cells. We measured the activin activity of the Xenopus egg extract by using an erythroid-differentiating test with Friend leukemia cells. The results showed that an activin homologue is, indeed, contained in unfertilized eggs and blastulae of Xenopus laevis in a considerable amount. This activity was eluted at the same retention time as human activin A when fractionated by reversed-phase HPLC. Furthermore, the fraction containing erythroid-differentiating factor activity had mesoderm-inducing activity on Xenopus animal-cap cells. The mesoderm-inducing activity of this fraction was suppressed when coincubated with follistatin, an activin-binding protein. These results suggest that an endogenous activin may be a natural mesoderm-inducing factor acting in Xenopus embryogenesis.
Asashima
M
M
Department of Biology, Yokohama City University, Japan.
Nakano
H
H
Uchiyama
H
H
Sugino
H
H
Nakamura
T
T
Eto
Y
Y
Ejima
D
D
Nishimatsu
S
S
Ueno
N
N
Kinoshita
K
K
D028341:Activins; D000818:Animals; D001681:Biological Assay; D001755:Blastocyst / Q000737:chemistry* / Q000166:cytology / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007265:Inhibins / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D008648:Mesoderm / Q000187:drug effects / Q000502:physiology*; D009865:Oocytes / Q000737:chemistry* / Q000166:cytology / Q000502:physiology; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D014982:Xenopus laevis
D011994:Recombinant Proteins; D028341:Activins; D007265:Inhibins