McBurney, K.M., and G.M. Wright, 1996. Chondrogenesis of a Non-collagen-based Cartilage in the Sea Lamprey, Petromyzon marinus, Atlantic Veterinary College

Reprinted from Canadian Journal of Zoology (1996) 74: 2118-2130

Chondrogenesis of a Non-collagen-based Cartilage in the Sea Lamprey, Petromyzon marinus

Abstract:
Chondrogenesis of the trabeculae, non-collagen-based cartilages in prolarval stages of the sea lamprey. Petromyzon marinus, was examined by light and electron microscopy. Chondrogenesis of the trabecular cartilages in prolarval lampreys commenced with the formation of mesenchymal condensations. Two peaks in mesenchymal cell density occurred, one prior to condensation formation and a second immediately before cartilage differentiation. The possibility of inductive influences by epithelio-mesenchymal interactions on the initiation of chondrogenesis is discussed. Bilateral condensations first appeared by day 17 post fertilization ventromedial to the eyes in a band of tightly packed yolk-laden mesenchymal cells that represent neural crest derived tissue. Cartilage differentiation occurred by day 19 post fertilization and was indicated by the presence of matrix-synthesizing organelles and the first ultrastructural appearance in the extracellular matrix of lamprin, a structural protein unique to lamprey cartilage. Lamprin was initially deposited as discrete 15 to 40-nm globules. Subsequently, lamprin appeared as fibrils aggregated into branching and parallel arrays arranged in pericellular, territorial, and interterritorial zones. Lengthening of the trabecular cartilages was primarily by appositional growth at the rostra1 end. The timing of the appearance of trabecular cartilages in prolarval stages likely reflects the functional importance of these structures for supporting the brain as the lamprey initiates burrowing behaviour.

Entire Paper
Contact: K.M. McBurney, Department of Anatomy and Physiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE C1A 4P3
Keywords: Sea_lamprey
Product Type: Research, Basic_biology
User Type: General