Worm Breeder's Gazette 5(2): 19
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 major components of the cuticle were found, in Ascaris des to be proteins (Bird 1956), the most important being collagen (Watson and Silvester 1959; Josse and Harrington 1964). In order to obtain this major protein, intact cuticles from C. elegans were isolated by sonication and incubation with 1% SDS, according to the method described by M. Kusch at the Woods-hole workshop. The purity of the preparation and the preservation of the in situ characteristics of the isolated cuticles were controlled by electron microscopy. Proteins represent about 65% of the dry weight of the isolated cuticles and collagen 70% of the proteins. Taking into account the fact that the cuticle is soluble in reducing solutions, as is the case for Ascaris (Evans et al. 1976), we prepared the C. elegans cuticle collagen by reduction with -mercaptoethanol in a buffer containing 8M Urea followed by carboxymethylation with sodium Iodoacetate. This collagen analyzed by SDS-Polyacrylamide gel electrophoresis gave seven bands (fig.). Their molecular weights are : 185000, 155000, 92000, 65000 (the predominant band) 51000, 32000, 20000 (the gamma, 11 and alpha1 components of Calf skin Type I Collagen were taken for calibration). All these components are sensitive to bacterial collagenase. The C. elegans cuticle collagen was submitted to molecular sieve chromatography and now to ion exchange chromatography on phosphocellulose to obtain purified components. [See Figure 1] The amino acid composition of the cuticular collagen of C. elegans and the fractions obtained by molecular sieve chromatography showed high hydroxyproline content (10%) and low proline content (13%) compared to Ascaris cuticle collagen (2% and 36% respectively, Evans et al. 1976). The proline and hydroxyproline contents are close to those found in vertebrate collagen. But like all known invertebrate cuticle collagen, C. elegans lacks hydroxylysine. The aim of the present work is to determine whether the separated components are genetically distinct chains and could represent different collagen types, or if these components all belong to the same type of collagen.