Collagen fibrils of an invertebrate (Sepia officinalis) are heterotypic: immunocytochemical demonstration.
Collagen fibrils from the dermis of Sepia officinalis were processed for immunoelectron microscopy to reveal reactions to antibodies against mammalian types I, III, and V, teleost type I and cephalopod type I-like collagens, by single and double immunogold localization. The fibrils were observed: (a) in suspensions of prepared fibrils, (b) in ultrathin sections of embedded fibril preparations, and (c) in ultrathin sections of dermal tissue. Some samples were subjected to acetic acid or urea dissociation. It was found that collagen fibrils from Sepia dermis are heterotypic in that they are composed of type I-like and type V collagens. Type I-like collagen epitopes were present mainly at the periphery of the fibrils; type V collagen epitopes were present throughout the fibrils. This is the first demonstration that collagen fibrils from an invertebrate are heterotypic, suggesting that heterotypy may be an intrinsic characteristic of the fibrils of fibrillar collagens, independent of evolutionary or taxonomic status.
Bairati
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A
Dipartimento di Scienze Biomolecolari e Biotecnologie, Università di Milano, Via Celoria 26, 20133 Milan, Italy. aurelio.bairati@unimi.it
Gioria
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M
D000818:Animals; D000906:Antibodies / Q000276:immunology; D024022:Fibrillar Collagens / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D008974:Mollusca / Q000737:chemistry* / Q000378:metabolism
D000906:Antibodies; D024022:Fibrillar Collagens