Muscle deficiency and neonatal death in mice with a targeted mutation in the myogenin gene

A muscle specific transcription factor that can induce myogenesis in a variety of cell types is myogenin. To test myogenin's role in embryonic muscle development, homozygous mice were generated for a targeted mutation in the myogenin gene. Though these mice survived fetal development, they were born immobile and died immediately after birth. They have severe reduction in their skeletal muscle throughout their body. Myogenin is thus an essential component for the skeletal muscle formation during embryogenesis. Mice lacking myogenin have gross rib defects, which are not revealed at the cellular level as bone and cartilage appear histologically normal.