[Ultrastructure of the oocyte nucleus and cytoplasm in the mollusk, Littorina saxatilis. I. The structure of the meiotic chromosomes and of the products of their activity in the period of great oocyte growth].
At the beginning of the early diplotene, the chromosomes are getting despiralized and are seen to be made of a mass of fibrous material and chromocentres. During previtellogenesis the chromosomes are made of fibrilles 4--20 nm in diameter. At the beginning of vitellogenesis nucleolus-like bodies are seen to appear on bivalents made of granules (25--30 nm) and fine fibrilles. At the same time, in association with chromosomes a structure of irregular form was observed made of granules 25--30 nm in diameter and a string 20 nm in diameter. This structure is analogous to granular loops of the lampbrush chromosomes of the amphibia. During the large growth of the oocyte perichromatin and interchromatin granules are seen in the nuclei. By the end of the large growth numerous protein spheres, formed by fibrilles 12--13 nm in diameter are seen on the chromosomes. It is concluded that chromosomes of the L. saxatilis oocytes function as the lampbrush chromosomes of the amphibia and other animals having the solitary type oogenesis.
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002875:Chromosomes / Q000648:ultrastructure*; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D008540:Meiosis; D008974:Mollusca / Q000648:ultrastructure*; D009865:Oocytes / Q000254:growth & development / Q000648:ultrastructure*; D010063:Ovum / Q000648:ultrastructure*; D011418:Prophase
Ul'trastruktura iadra i tsitoplazmy ootsitov molliuska Littorina saxatilis. I. Stroenie meioticheskikh khromosom i produktov ikh aktivnosti v period bol'shogo rosta ootsitov.