[An electron microscopic study of lamp-brush chromosomes and the products of their activity during rabbit oogenesis].
An ultrastructural study of the rabbit oocyte nucleus was started from the early diplotene and extended to the large growth period to include the bilaminar follicle stage. During the large growth, the rabbit oocytes do not develop to the dictyate or "resting" stage, but remain at the diplotene. At the period preceeding the large growth (the early diplotene) lampbrush chromosomes are revealed made of the central axis 50 nm in diameter wish lateral fibrils. The aggregation of long loosely arranged fibrils makes the chromosome matrix. In the fibrillar zone of the chromosome, numerous roundish granules ca 45 nm in diameter and dense granule accumulations ca 0.15 mkm in diameter were visualized. Large fibrogranular bodies (1--2 mkm in diameter) are seen in association wish chromosomes. All these extra-nuclear bodies that appear on chromosomes differ in their size and pattern. These, likely as the nucleoli, may be considered as morphological expression of the genic activity of lampbrush chromosomes.
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002682:Chinchilla; D002875:Chromosomes / Q000648:ultrastructure*; D005260:Female; D009865:Oocytes / Q000648:ultrastructure*; D009866:Oogenesis; D010063:Ovum / Q000648:ultrastructure*; D011817:Rabbits
Elektronnomikroskopicheskoe issledovanie khromosom tipa lampovykh shchetok i produktov ikh aktivnosti v oogeneze krolika