Caenorhabditis elegans cuticle: a description of new elements of the fibrous layer.

At the ultrastructural level, the Caenorhabdits elegans cuticle shows the presence of well defined layers; 1 of them is the fibrous layer composed by 2 strands of fibers that meet each other at a 60 degrees angle and resembling a fish-bone pattern. In this paper, we describe new elements of the fibrous layer. When thin sections were obtained at a very low angle, i.e., almost tangential, fibers of wavy appearance could be observed. Those elements were 300 nm in length and 20 nm thick and were linked to each other by delicate dots. Deep-etched replicas of C. elegans revealed more details of the arrangement of new elements in the fibrous layer. The wavy fibers were organized in 5-sided, honeycomblike figures. Each pentagonal fiber was 145 nm across and was composed of tightly packed globular structures arranged linearly.