Worm Breeder's Gazette 2(1): 20

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

The Cuticle of C. elegans

J. Laufer, B. Edgar, M. Kusch, A. Pillsbury

We are starting to study the structure and genetic control of the C. 
elegans cuticle.  Cuticles free of most contaminating tissue can be 
obtained by gentle homogenization or sonication followed by extensive 
washing with or without SDS.  Such cuticles reveal many structural 
features in phase contrast observation.  Cuticle material not only 
covers the outer surface but continues into the anal opening and the 
lining of the pharynx.  The pharynx apparently also has a lining of 
SDS-resistant material separating it from the body proper.  The 
cuticle appears to be composed of two layers which are held together 
by 'struts'.  The struts form a quite regular pattern consisting of a 
double row at the boundary between the annulae.  Mild treatments with 
Pronase or Collagenase appear to act most readily by breaking the 
struts resulting in the formation of 'double-bags'.  Continued 
treatment results in the dissolution of the inner 'bags'.  In addition 
to being relatively resistant to enzymatic digestion, the outer layer 
is much more resistant to a variety of non-enzymatic treatments that 
break non-covalent or disulphide bonds.  Adults and dauer larvae have 
the familiar cuticular structure with annulae and lateral treads (
ridges, alae), although the structure of the tread differs in the two 
forms.  Other larval forms (L3, L4), not yet precisely characterized, 
lack these structural features.  We are about to attempt chemical 
characterization of the isolated cuticle.
The cuticles of dumpy, roller and blister mutants display abnormal 
cuticular features.  In blister mutants the blisters form between the 
two cuticle layers with the struts clearly broken or missing.  The 
cuticles removed from roller animals are helically twisted, in some 
cases these cuticles physically curl up even more after the animal is 
removed.  The annulae are not arranged at right angles to the treads 
as in a normal animal.  Mutants with an extreme roller phenotype, and 
some dumpies, have aberrant treads displaying multiple loops and 
breaks.  These observations encourage us in our suspicion that at 
least some of the genes that generate these phenotypes are concerned 
with cuticle formation.
Unsolicited gifts of newly isolated roller or blister mutants will 
be gratefully accepted.