A dominant negative bone morphogenetic protein 4 receptor causes neuralization in Xenopus ectoderm.
Injection of DN-BR mRNA encoding a dominant negative type I receptor for bone morphogenetic protein 4 (BMP4) converted prospective ectoderm into neural tissue in Xenopus animal cap explants, in the absence of expression of mesodermal marker genes. The injected caps expressed a general neural marker NCAM and the forebrain marker opsin. Coinjection of wild-type BMP4 receptor mRNA completely reversed the neuralization by DN-BR. No expression of known neuralizing factors, i.e., noggin and follistatin, was detected in the DN-BR-injected animal caps. Furthermore, neuralization elicited by noggin or 3m, a LIM domain mutant of Xlim-1, was substantially inhibited by co-injection of BMP4 mRNA. Since BMP4 is expressed in the prospective ectoderm during gastrulation, our results suggest that the ventralizing factor BMP4 acts also as a physiological inhibitor of neuralization in the development of Xenopus ectoderm.
Xu
R H
RH
Laboratory of Biochemical Physiology, BRMP, NCI-FCRDC, NIH, Frederick, MD 21702-1201, USA.
Kim
J
J
Taira
M
M
Zhan
S
S
Sredni
D
D
Kung
H F
HF
D000818:Animals; D001483:Base Sequence; D052004:Bone Morphogenetic Protein Receptors; D019485:Bone Morphogenetic Proteins; D002454:Cell Differentiation; D017931:DNA Primers; D004475:Ectoderm / Q000166:cytology* / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology*; D005314:Embryonic and Fetal Development; D015870:Gene Expression; D006133:Growth Substances / Q000378:metabolism; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000008:administration & dosage / Q000096:biosynthesis / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000502:physiology*; D017978:Receptors, Growth Factor; D014982:Xenopus laevis
D019485:Bone Morphogenetic Proteins; D017931:DNA Primers; D006133:Growth Substances; D011506:Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017978:Receptors, Growth Factor; D052004:Bone Morphogenetic Protein Receptors