BMP7 null mutation in mice: developmental defects in skeleton, kidney, and eye

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Transgenic mouse models are crucial for understanding gene function.
• Insertional mutagenesis can lead to gene inactivation and observable phenotypes.
• Bone Morphogenetic Protein 7 (BMP7) is part of the TGF-beta superfamily, suggesting a role in development.

Purpose of the Study:

• To determine the molecular basis of a severe developmental defect observed in transgenic mouse offspring.
• To investigate the role of the Bone Morphogenetic Protein 7 (BMP7) gene in mammalian development.

Main Methods:

• Generation of bcl2 alpha transgenic mice.
• Screening of a genomic library from affected transgenic lines using a transgene-specific probe.
• Analysis of the phenotype in F2 offspring exhibiting developmental abnormalities.

Main Results:

• Identification of Bmp7 gene inactivation by insertional mutagenesis in affected mice.
• Homozygous Bmp7 null mice exhibit a postnatal lethal phenotype.
• Observed developmental defects include skeletal abnormalities (bone, cartilage, vertebrae, limbs, tail), kidney malformations (reduced nephrons, polycystic kidney), and eye defects (retinal pigmentation, lens development).

Conclusions:

• BMP7 is essential for normal mammalian skeletal development.
• BMP7 plays a critical role in kidney development and function.
• BMP7 signaling is vital for proper eye development, including retinal and lens formation.