title: Heart formative factor(s) is localized in the anterior endoderm of early Xenopus neurula.
abstract: To elucidate the mechanisms of early heart morphogenesis in Xenopus laevis, we examined the effect of endoderm on heart morphogenesis in the early Xenopus neurula. Explants of anterior ventral (presumptive heart) mesoderm from early neurula were cultured alone or in combination with endoderm dissected from various regions. Heart formation was scored by an original heart index based on morphology. These explant studies revealed that anterior ventral endoderm plays a critical role in heart morphogenesis. Furthermore, we found that it was possible to confer this heart-forming ability on posterior ventral endoderm by the injection of poly(A)+RNA from stage 13 anterior endoderm. These results imply that the heart formative factor(s) is localized in the anterior endoderm of the early neurula and that at least part of this activity is encoded by mRNA(s).
authors.affiliation: Faculty of Pharmaceutical Sciences Hokkaido University, 060, Sapporo, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Tonegawa
authors.affiliation: Division of Biological Sciences, Graduate School of Science, Hokkaido University, 060, Sapporo, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Moriya
authors.affiliation: Faculty of Pharmaceutical Sciences Hokkaido University, 060, Sapporo, Japan.
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tada
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, 305, Tsukuba, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nishimatsu
authors.affiliation: Division of Biological Sciences, Graduate School of Science, Hokkaido University, 060, Sapporo, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Katagiri
authors.affiliation: Faculty of Pharmaceutical Sciences Hokkaido University, 060, Sapporo, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Ueno
keywords: Endoderm; Heart morphogenesis; Xenopus laevis