FREEZE-FRACTURE AND DEEP-ETCHED VIEW OF THE CUTICLE OF CAENORHABDITIS-ELEGANS

At ultrastructural level, the Caenorhabditis elegans (C. elegans) cuti cle shows the presence of well-defined layers, one of them is a membra ne-like structure designated as epicuticle, always present on the oute rmost surface of nematodes, Freeze-fracture replicas revealed the exis tance of two faces of the epicuticle: a inner face containing numerous particles, and a almost smooth outer face, Deep etching replicas conf irmed the existance of these two faces of the epicuticle showing in so me replicas two particle populations on the outer face of L4 and adult forms of C. elegans. Also a previously unrecognized structure was not ed in the cuticle of C. elegans, a matrix composed by network of globu lar and filamentous structures, leaving in between them spaces, which probably are occupied by water in the living adult and L4 larvae speci men, This network demonstrates either a compact nature or loose nature according to their cuticle location. Deep etching replicas of the adu lts nematode revealed large spaces between the cortical and basal laye rs which are regularly interrupted by struts connecting each other by fibers in a particular arrangement.