A radioautographic study of collagen synthesis by earthworm epidermis.

Secreation by the epidermis of two oligochaetes (Eisenia and Enchytraeus) was investigated radioautographically following administration of 3H-proline, 3H-tryptophan or Na2(35)SO4. Regionally epidermal columnar cells of Enchytraeus synthesize the overlying, probably collagenous, cuticle. Eisenia epidermis does not recordably synthesize the cuticle until after wounding (first eight segments removed). By two days postoperative the epidermal columnar cells of Eisenia synthesize the collagenous cuticle and, later in regeneration, the epidermis may simultaneously synthesize the different collagen of the underlying basement lamella. The epidermis of Enchytraeus, but not of Eisenia, synthesizes some sulfated material associated with the cuticle surface.