Summary of mutant phenotypes
Agrin -/-: few ACh-R clusters, overshooting of axons
MuSK -/-: no ACh-R clusters, overshooting of axons
Rapsyn -/-: no ACh-R clusters, but higher receptor
levels in synaptic area, only limited overshooting
Pre-synaptic defects in all mutants, due to the lack of
retrograde signals from the muscle