Collagenous and other organizations in mature annelid cuticle and epidermis

Abstract

The mature annelid cuticle contains orthogonally oriented collagen in a matrix capped superficially by a dense epicuticle with external corpuscles. The underlying epidermis is a simple columnar epithelium with two major cell types, mucous-secreting cells which secrete through channels in the cuticle to the exterior of the worm, and "supportive" cells which presumably produce and increase the cuticle by secreting into it. The structures of supportive cells, previously interpreted as specialized for establishing interfibrillar collagen order, are revealed by glutaraldehyde fixation as common cellular components without the qualities deemed useful to align collagen. Cell processes which penetrate and sometimes pass completely through the cuticle are not stable, not in geometric order, and lack cilia-like structure. Cilia, unlike the ubiquitous cellular processes, are highly restricted to regions of the epidermis with specialized functions. Cellular control, or other control, of collagen fibrillogenesis remains unestablished.

A transmission and scanning electron microscopy study of the cuticle and epidermis of Pomatoceros lamarckii (Polychaeta: Serpulidae)

“…The body surface of annelids is covered by an external cuticle secreted by epidermal cells. In a number of annelids the cuticle has been demonstrated to be composed of collagen secreted by epidermal cells (Fujimoto & Adams, 1964;Josse & Harrington 1964;Kimura, 1971;Burke & Ross, 1975;Humphreys & Porter 1976~). Annelid cuticle collagen is an unusual collagen of particular interest because it is ectodermal in origin, unlike most other invertebrate and vertebrate collagens, which are mesodermal (Porter, 1966;Rudall, 1968).…”

Elektronenmikroskopische Untersuchungen anAnaitides mucosa (Annelida, Polychaeta). Cuticula und Cilien, Schleimzellen und Schleimextrusion

“…Ein Charakteristikum des Schleimzellenapex ist es, dab mehr oder weniger deutlich Abb. 6 (Eckelbarger & Chia, 1978;Holborow, 1971;Holborow et al, 1969} sowie zur Regeneration der Polychaetencuticula (Humphreys & Porter, 1976) (Friedrich, 1964;Richards, 1978). Die Cuticula von A. mucosa ist in der Tat so regelm~il~ig aufgebaut, dal~ eine derartige Interpretation zumindest einen Teil der FSrbung erkl~irt.…”

Invertebrate Collagens

“…Table 1 summarizes the distribution of collagen among invertebrate phyla. Because most of the (24,67,92) Ascaris (14, 31-33, 35-37, 39, 45, 47, 49, 51, 52, 55, 80-82, 84, 94, 110-112), Nematospiroides (113), Nippostrongylus (113), Panagrellus (38,85,114) Hirudinea (115), Lumbricus (15, 39, 45, 48, 54, 61, 62, 76, 79, 94, 107, 111-113, 116, 117), other Oligochaeta (15,40,47,115,(117)(118)(119)(120), Polychaeta (41,42,72,115,120) Macracanthorhynchus (26,47) Cephalopoda (29,48,57,72,73,107,121), Haliotis (29,72), Helix (60,67,115,122), Mytilus (48,99,107,115,123,124) Arachnida (125), Crustacea …”

“…While this central set of related properties can be used to define all proteins classed as collagens, other features considered characteristic of collagen show considerable variation. Thds, by the criteria above, there is at least one collagen with no measurable hydroxyproline (12) or with little (13) or no (14) hydroxylysine, and there are collagens with rather different banding periods in the electron microscope (9,15), or with no banding at all (9,16).…”