Some observations on the fine structure of the enclostyle of larval lampreys, ammocoetes of Lampetra japonica

摘要: The endostyle of larval lampreys, ammocoetes Lampetra japonica was studied with the electron microscope. Type 1 cells in dorsal as well ventral lobules are characterized by a well-developed granular endoplasmic reticulum occupying most cytoplasm. Two kinds cytoplasmic granules occur type cells: large less-dense and small dark. dark ones, corresponding to aldehyde-fuchsinopbile aldehyde-thioninophile substances, gathered processes that terminate at endostylar lumen. Both apparently produced Golgi apparatus system, may be protein-secretory substances. 2 cells, cylindrical shape, numerous cilia microvilli, contain free ribosomes, glycogen particles, few lysosome-like dense bodies. In addition, 2c elements retieulum. 3 cell, principal iodine-concentrating microvilli relatively fewer, is fairly developed, some continuous zone. Small vesicles, which might derived from apparatus, located apical part These considered secretory materials containing thyroglobulin. A number particles widely distributed. immature or transitional lying between low height ribosomes particles. There very reticulum. 4 process, has distributed vesicles. scarce. 5 forming lining chamber, flattened cuboidal smooth heterogeneous bodies, lack microvilli. all this type.