About the cover
After injury to the nervous system in the nematode Caenorhabditis elegans, an axon sprouts new growth towards its detached segment; a membrane-tethered fluorophore is shown in blue, and the cytoplasm magenta. Fragments are slightly repositioned for clarity. Massimo Hilliard and colleagues provide a detailed analysis of a highly efficient means of regeneration in the C. elegans nervous system known as axonal fusion, in which separated axon segments are able to spontaneously reconnect and fuse to restore the original circuitry. Fusion in this context prevents the breakdown of the detached axon segment and requires regeneration only to bridge the region of damage. The authors investigate the molecular machinery required for this regenerative process, and find that it begins with changes to the phospholipid composition of the axonal membrane followed by recruitment of specific molecules in the regrowing axon as well as from surrounding tissues. Remarkably, the molecules and mechanisms discovered in this process mirror those involved in the recognition and engulfment of apoptotic cells by phagocytes. Cover design by Nick Valmas, image by Casey Linton.