Ephrin-A3 promotes and maintains slow muscle fiber identity during postnatal development and reinnervation.

ABSTRACT: Each adult mammalian skeletal muscle has a unique complement of fast and slow myofibers, reflecting patterns established during development and reinforced via their innervation by fast and slow motor neurons. Existing data support a model of postnatal "matching" whereby predetermined myofiber type identity promotes pruning of inappropriate motor axons, but no molecular mechanism has yet been identified. We present evidence that fiber type-specific repulsive interactions inhibit innervation of slow myofibers by fast motor axons during both postnatal maturation of the neuromuscular junction and myofiber reinnervation after injury. The repulsive guidance ligand ephrin-A3 is expressed only on slow myofibers, whereas its candidate receptor, EphA8, localizes exclusively to fast motor endplates.

SUBMITTER: Stark DA 

PROVIDER: S-EPMC4674275 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature