Record Details
Field | Value |
---|---|
Title | The fine structure of the fibrillar club cell in the epidermis of Lampetra planeri (Bloch) |
Names |
Morse, Howard Curtis
(creator) Dornfeld, Ernst J. (advisor) |
Date Issued | 1963-05-14 (iso8601) |
Note | Graduation date: 1963 |
Abstract | The epidermis of the brook lamprey, Lampetra planers (Bloch), has been examined with histological and histochemical techniques and the fine structure of the fibrillar club cells has been studied with electron microscopy. In histological structure the epidermis was found to correspond to the observations of earlier workers. The stratified epidermis possesses three cell types: (1) ordinary epithelial cells in all layers, (2) fibrillar club cells in the basal layer, and (3) granular cells in the intermediate layer. The periodic acid Schiff test for polysaccharides was negative in the fibers of the club cells but positive in the ordinary epithelial cells, especially those towards the surface. The large granular cells are only slightly P.A.S. positive. Masson's trichrome stain indicated that the fibers of the club cells stain inconsistently, but usually unlike either collagen or keratin. Chevremont and Frederic's ferricyanide test for sulfhydryl groups was only slightly positive in the fibers when employed alone. Upon pre-treatment with thioglycollate the staining of the fibers notably increased compared to surrounding proteins, indicating that many disulfide linkages were reduced to sulfhydryl groups. The electron microscope revealed that the fibers seen in the light microscope are aggregations of small filaments with a diameter of 115 to 150 A[superscript ⁰]. These filaments fill most of the cell except for a small apical region and a vertical core through the center. This area of more typical cytoplasm contains two nuclei, many large mitochondria, two sizes of vesicles and numerous small granules. The basal surface of the club cell lies next to an adepidermal "space ", a zone of low electron density, and an adepidermal membrane of high electron density. Below this lies the basement lamella composed of 10 to 15 orthogonally arranged layers of collagen fibrils. Numerous large plaques occur along the basal plasma membrane at irregular intervals. The intracellular filaments appear to terminate or originate in the plaques as do extracellular projections extending from the adepidermal membrane. The club cell surface adjacent to other epithelial cells is very tortuous in outline and much interdigitation with neighboring cells occurs. Fewer and smaller desmosomes are present on the club cell surface than on the interfaces of surrounding cells. The extracellular matrix is less abundant around club cells than around other epithelial cells and their matrix occasionally includes granules. |
Genre | Thesis/Dissertation |
Topic | Epidermis |
Identifier | http://hdl.handle.net/1957/49426 |