Bmpr encodes a type I bone morphogenetic protein receptor that is essential for gastrulation during mouse embryogenesis.
Bone morphogenetic proteins (BMPs) are secreted proteins that interact with cell-surface receptors and are believed to play a variety of important roles during vertebrate embryogenesis. Bmpr, also known as ALK-3 and Brk-1, encodes a type I transforming growth factor-beta (TGF-beta) family receptor for BMP-2 and BMP-4. Bmpr is expressed ubiquitously during early mouse embryogenesis and in most adult mouse tissues. To study the function of Bmpr during mammalian development, we generated Bmpr-mutant mice. After embryonic day 9.5 (E9.5), no homozygous mutants were recovered from heterozygote matings. Homozygous mutants with morphological defects were first detected at E7.0 and were smaller than normal. Morphological and molecular examination demonstrated that no mesoderm had formed in the mutant embryos. The growth characteristics of homozygous mutant blastocysts cultured in vitro were indistinguishable from those of controls; however, embryonic ectoderm (epiblast) cell proliferation was reduced in all homozygous mutants at E6.5 before morphological abnormalities had become prominent. Teratomas arising from E7.0 mutant embryos contained derivatives from all three germ layers but were smaller and gave rise to fewer mesodermal cell types, such as muscle and cartilage, than controls. These results suggest that signaling through this type I BMP-2/4 receptor is not necessary for preimplantation or for initial postimplantation development but may be essential for the inductive events that lead to the formation of mesoderm during gastrulation and later for the differentiation of a subset of mesodermal cell types.
Department of Molecular Genetics, University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA.
Y
Y
Mishina
A
A
Suzuki
N
N
Ueno
R R
RR
Behringer
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D052005:Bone Morphogenetic Protein Receptors, Type I; D019485:Bone Morphogenetic Proteins; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D047108:Embryonic Development; D005314:Embryonic and Fetal Development / Q000235:genetics*; D005260:Female; D005775:Gastrula; D018507:Gene Expression Regulation, Developmental; D005804:Genes, Lethal; D005808:Genes, Recessive; D018095:Germ-Line Mutation; D006579:Heterozygote; D006720:Homozygote; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D011247:Pregnancy; D011506:Proteins / Q000235:genetics*; D013737:Testis / Q000166:cytology / Q000196:embryology / Q000378:metabolism
D019485:Bone Morphogenetic Proteins; D011506:Proteins; C498212:Bmpr1a protein, mouse; D052005:Bone Morphogenetic Protein Receptors, Type I