tom-1(ok285) Mutants Accumulate Vesicles That Are Contacting the Plasma Membrane

(A) Examples of synaptic profiles from WT and tom-1(ok285) neuromuscular synapse prepared by high-pressure freeze and freeze substitution. The presynaptic density is labeled PD, and the plasma membrane-contacting vesicles are indicated with arrows. Scale bar, 100 nm.

(B) Vesicles contacting the plasma membrane as a ratio of total vesicles per synaptic profile are increased in tom-1(ok285) mutant animals.

(C) The distribution of plasma membrane-contacting vesicles relative to the presynaptic density, expressed in 30-nm bins as a ratio of total vesicles per profile for WT and tom-1(ok285).

(D) Schematic representation of data in (C) depicting the distribution of vesicles contacting plasma membrane (black circles for WT, purple circles for tom-1 mutants) relative to the presynaptic density. Data expressed as mean ± SEM.