Requirement of Bmp8b for the generation of primordial germ cells in the mouse

Mol Endocrinol. 2000 Jul;14(7):1053-63. doi: 10.1210/mend.14.7.0479.


In the mouse embryo, the generation of primordial germ cells (PGCs) from the epiblast requires a bone morphogenetic protein-4 (BMP4) signal from the adjacent extraembryonic ectoderm. In this study, we report that Bmp8b, a member of the Gbb-60A class of the BMP superfamily, is expressed in the extraembryonic ectoderm in pregastrula and gastrula stage mouse embryos and is required for PGC generation. A mutation in Bmp8b on a mixed genetic background results in the absence of PGCs in 43% null mutant embryos and severe reduction in PGC number in the remainder. The heterozygotes are unaffected. On a largely C57BL/6 background, Bmp8b null mutants completely lack PGCs, and Bmp8b heterozygotes have a reduced number of PGCs. In addition, Bmp8b homozygous null embryos on both genetic backgrounds have a short allantois, and this organ is missing in some more severe mutants. Since Bmp4 heterozygote embryos have reduced numbers of PGCs, we used a genetic approach to generate double-mutant embryos to study interactions of Bmp8b and Bmp4. Embryos that are double heterozygotes for the Bmp8b and Bmp4 mutations have similar defects in PGC number as Bmp4 heterozygotes, indicating that the effects of the two BMPs are not additive. These findings suggest that BMP4 and BMP8B function as heterodimers and homodimers in PGC specification in the mouse.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bone Morphogenetic Protein 4
  • Bone Morphogenetic Proteins / genetics*
  • Bone Morphogenetic Proteins / metabolism
  • Ectoderm / cytology
  • Embryo, Mammalian / cytology*
  • Female
  • Gastrula / cytology
  • Gene Expression Regulation, Developmental
  • Germ Cells / physiology*
  • Homozygote
  • Male
  • Mesoderm / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred Strains
  • Mice, Mutant Strains
  • Mutation


  • Bmp4 protein, mouse
  • Bmp8b protein, mouse
  • Bone Morphogenetic Protein 4
  • Bone Morphogenetic Proteins