Gruzova M N, Parfenov V N
Tsitologiia. 1976 Mar;18(3):261-74.
The ultrastructural organization of the vitellogenic oocyte nucleus (stage VI, according to Duryee, 1950) was studied in normal and in vitro hormone-stimulated maturing oocytes of Rana temporaria. At this stage, numerous nucleoli are gathered around the knot of highly contracted chromosomes (the karyosphere) thus making the karyosphere capsule. Light microscope observations reveal three zones in the capsule: a central fibrous zone separating the chromosomes from the nucleoli, a middle zone, consisting of numerous nucleoli and a distinct fibrous componen; in addition a fibrous zone on the capsule periphery is seen. The nucleoli are fibrillar, bear no proribosomal granules and do not synthesize RNA. This period is characterized by an intensive fragmentation and segregation of the nucleolar material. Numerous micronucleoli and nuclear bodies occur in the nucleus. The nucleoli are normally compound and irregular in shape to become spherical in hormone-stimulated maturing oocytes. In the central fibrous zone of the capsule, separating the chromosomes from the nucleoli, some peculiar abundant accumulations of annuli were detected lacking the membranes component. Annuli are linked with the fibrous material and are regularily packed making peculiar pseudomembranes (PMM). The chromatin is connected with PMM directly. In the middle zone of the capsule, accumulations of PMM are also seen, though less abundant and less regularly packed; along with annuli, membranous areas of various size and form are met in PMM. PMM are connected with the micronucleoli with filaments 20 nm thick. In the peripheral zone of the capsule, a variety of membranous structures is detected: intranuclear annuli lamellae, component of the capsule consists of different membranous and pseudomembranous (with annuli) structures. A question of the contribution of the chromatin material in the formation of the fibrous capsular component (PMM and membranous structures) is discussed.
在正常及体外激素刺激成熟的林蛙卵母细胞中，研究了卵黄发生期卵母细胞核（根据杜里伊1950年的分期为VI期）的超微结构组织。在此阶段，大量核仁聚集在高度收缩的染色体结（核球）周围，从而形成核球囊。光学显微镜观察显示，该囊中有三个区域：一个中央纤维区，将染色体与核仁分开；一个中间区，由大量核仁及一个明显的纤维成分组成；此外，在囊的周边可见一个纤维区。核仁呈纤维状，没有前核糖体颗粒，也不合成RNA。这一时期的特点是核仁物质强烈碎片化和分离。细胞核中出现大量微核仁和核体。核仁通常呈复合状且形状不规则，在激素刺激成熟的卵母细胞中变为球形。在囊的中央纤维区，将染色体与核仁分开，检测到一些特殊的、丰富的环状物堆积，缺乏膜成分。环状物与纤维物质相连，规则排列形成特殊的假膜（PMM）。染色质直接与PMM相连。在囊的中间区，也可见到PMM的堆积，不过数量较少且排列不那么规则；在PMM中，除了环状物外，还可见到各种大小和形状的膜性区域。PMM通过20纳米厚的细丝与微核仁相连。在囊的周边区，检测到多种膜性结构：核内环状片层，囊的成分由不同的膜性和假膜性（含环状物）结构组成。文中讨论了染色质物质在纤维状囊成分（PMM和膜性结构）形成中的作用问题。
