Article

The biology of cartilage. I. Invertebrate cartilages: Limulus gill cartilage

Ames Research Center, NASA, Moffett Field, California 94035
Journal of Morphology (Impact Factor: 1.55). 05/1969; 128(1):67 - 93. DOI: 10.1002/jmor.1051280104

ABSTRACT The endoskeletal structure supporting the gill-books of Limulus polyphemus has been investigated by means of light and electron microscopy, chemical analysis and x-ray diffraction. This tissue is a cartilage which has significant correspondences with both vertebrate cartilage and plant tissues. Morphologically, the Limulus cartilage resembles certain cellular vertebrate cartilages with relatively scant matrix, and also certain plant parenchyme, collenchyme and sclerenchyme tissues. Of particular interest, was the observation that during cytoplasmic division, a phragmasome-like structure appears between the daughter cells of the dividing gill cartilage cells. This phragmasome-like structure appears to be a precursor of new matrix (cell-wall) formation between the young chondrocytes, in much the same fashion as its counterpart in plant tissues. Perichondrial cells and underlying chondrocytes contain lipid droplets, abundant glycogen and ribosomes, as do corresponding vertebrate cartilage cells. In some of the Limulus cells, glycogen and ribosomes appear to be admixed with lipid, forming aggregates in which all three materials are in intimate intraparticulate relationship. During molting, the number of ribosomes seen in chondrocytes increases. The tissue contains both hydroxyproline and hydroxylysine, and gives a weak x-ray diffraction pattern.

0 Followers
 · 
532 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: In both light and electron microscopes, head cartilage from the squid Loligo pealii strongly resembles vertebrate hyaline cartilage. The tissue is characterized by the presence of irregularly-shaped cells suspended in an abundant matrix. Cell and matrix contents stain metachromatically with cationic dyes such as toluidin blue. Each cell gives off extensions which ramify via a network of channels throughout the matrix. Thereby, a system of inter-connecting canaliculi is established, with many similarities to the intercanalicular systems seen in vertebrate bone and cartilage tissues. In the electron microscope, the squid cartilage cells are seen to have very abundant endoplasmic reticulum and Golgi complex material. Mitochondrial transformations involving loss of cristae, the appearance of filaments in the mitochondrial matrix, and figures suggesting budding, also occur. Nuclear pores are numerous and easily detected. The matrix is characterized by the presence of a system of decussating fibrils which form polygonal figures, with granules usually evident at the points of intersection of fibrils. By chemical analysis the tissue contains 3- and 4-hydroxyproline and hydroxylysine. Preliminary wide single x-ray diffractions show a pattern characteristic for unoriented collagens, with 12 Å (intermolecular) and 2.86 Å (helix) reflections.
    Journal of Morphology 08/1970; 131(4):417-30. DOI:10.1002/jmor.1051310405 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The cartilages (or "chondroid" tissue) in tentacles of the polychaete annelid, Sabella melanostigma, have been examined by electron microscopy and a series of histochemical techniques for the demonstration of mucopolysaccharides and protein end-groups. The ultrastructural studies indicated that the cartilages possess an investing layer of dense connective tissue which differs significanly from the matrix material secreted between the chondrocytes. The cartilage matrix was positive for acidic mucins with levels of sulfation above those of mammalian chondroitins A and C. This matrix as well as the investing connective tissue were intensely PAS-positive. Sabella cartilage was also stained intensely by methods for demonstrating tryptophan, tyrosine, side-chain carboxyl groups, disulfide groups, and amino groups. It was not stained by the procedure for sulfhydryl groups. Some evolutionary aspects of cartilage and chondroid tissues were discussed.
    Histochemistry 02/1975; 43(1):1-10. DOI:10.1007/BF00490150
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although invertebrate cartilage tissues do not mineralize in nature, it is now reported for the first time that when excised gill cartilage tissue from Limulus (horse shoe crab) is placed in an appropriate incubation medium metastable to hydroxyapatite, mineralization will occur. The mineralization is temperature dependent, and takes place at 37 degrees but not at 20 degrees. Incubations in media metastable to calcite have not produced mineralization. Histologic examination of mineralized tissues showed mineral deposits predominantly within cells, and to a lesser extent in the matrix. X-ray diffraction of the deposited mineral revealed a typical biological hydroxyapatite pattern.
    Calcified Tissue Research 01/1976; 19(2):85-90. DOI:10.1007/BF02563993
Show more