The mouse short ear skeletal morphogenesis locus is associated with defects in a bone morphogenetic member of the TGFβ superfamily

TLDR

The mouse short ear gene is essential for normal skeletal growth, patterning, and fracture repair, and its loss produces specific skeletal defects that indicate individual BMP family members dictate distinct aspects of bone and cartilage formation. The authors performed a comprehensive chromosome walk around the short ear locus to identify candidate genes. The short ear region contains the BMP‑5 gene, which is deleted or rearranged in multiple short ear mutations; homozygous deletions of Bmp‑5 are viable and fertile, making these mutations valuable for studying BMP functions in mammals.

Abstract

The mouse short ear gene is required for normal growth and patterning of skeletal structures, and for repair of bone fractures in adults. We have carried out an extensive chromosome walk in the chromosome region that surrounds this locus. Here we show that the short ear region contains the gene for a TGF beta-related protein called bone morphogenetic protein 5 (Bmp-5). This gene is deleted or rearranged in several independent mutations at the short ear locus. Mice homozygous for large deletions of the Bmp-5 coding region are viable and fertile. Mutations at the short ear locus provide an important new tool for defining the normal functions of BMPs in mammals. The specific skeletal defects seen in short-eared animals, which occur against a background of otherwise normal skeletal structures, suggest that particular aspects of skeletal morphology may be determined by individual members of a family of signaling factors that can induce the formation of cartilage and bone in vivo.