title: Spatiotemporal regulation of fibroblast growth factor signal blocking for endoderm formation in Xenopus laevis.
abstract: We have previously shown that the inhibition of fibroblast growth factor (FGF) signaling induced endodermal gene expression in the animal cap and caused the expansion of the endodermal mass in Xenopus embryos. However, we still do not know whether or not the alteration of FGF signaling controls embryonic cell fate, or when FGF signal blocking is required for endoderm formation in Xenopus. Here, we show that FGF signal blocking in embryonic cells causes their descendants to move into the endodermal region and to express endodermal genes. It is also interesting that blocking FGF signaling between fertilization and embryonic stage 10.5 promotes endoderm formation, but persistent FGF signaling blocking after stage 10.5 restricts endoderm formation and differentiation.
authors.affiliation: Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 700-412, Korea.
authors.forename: Sang-wook
authors.initials: SW
authors.lastname: Cha
authors.forename: Jong-Woo
authors.initials: JW
authors.lastname: Lee
authors.forename: Yoo-seok
authors.initials: YS
authors.lastname: Hwang
authors.forename: Jeong-Pil
authors.initials: JP
authors.lastname: Chae
authors.forename: Kwon Moo
authors.initials: KM
authors.lastname: Park
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Cho
authors.forename: Dong Sun
authors.initials: DS
authors.lastname: Kim
authors.forename: Yong Chul
authors.initials: YC
authors.lastname: Bae
authors.forename: Mae Ja
authors.initials: MJ
authors.lastname: Park
mesh_terms: D000818:Animals; D004707:Endoderm / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D017403:In Situ Hybridization; D011758:Pyrroles / Q000008:administration & dosage / Q000494:pharmacology; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D029867:Xenopus Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000502:physiology*
chemical_list: D011758:Pyrroles; D017468:Receptors, Fibroblast Growth Factor; C105686:SU 5402; D029867:Xenopus Proteins; D005346:Fibroblast Growth Factors