Biomaterial Database

[The organization of the karyosphere and capsule before oocyte maturation in the common frog]. 1994

G N Pochukalina, and V N Tsarfenov

The oocytes of the 6th stages, according to Dumont (1972), taken from R. temporaria in nature in April were studied. The semithin sections of Araldit-embedded material, as well as preparations of karyospheres with capsules isolated from nuclei using Callan's method (Callan et al., 1987), were analysed. Ultrastructural investigations were carried out both on intact nuclei and on nuclei extracted in 2M NaCl. The April oocytes differ from the winter ones previously analysed by Gruzova and Parfenov (1977), in the distribution of capsule components: the fibrous material surrounds, as previously, the central part of karyosphere, whereas the pseudomembranes penetrate into the chromosome tangle. The fibrous material reveals stability (resistance) to 2M NaCl treatment. Another feature of the April oocytes is the development of small intracellular bodies (0.3-2 microns). These bodies are composed of coiled threads 40-50 nm in diameter and connected with the nucleoli. The morphogenesis of the capsule fibrous component is discussed in connection with the double nature of the capsule material. Participation of actin filaments in the formation of the fibrillar part of the capsule is discussed. A similarity of the bodies composed of coiled threads in oocyte nuclei is drawn with the "coiled bodies" of somatic cell (Lamond, Carmo-Fonseca, 1993).

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D011896	Rana temporaria	A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.	European Common Frog,Frog, Common European,Common European Frog,Common Frog, European,European Frog, Common,Frog, European Common
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002875	Chromosomes	In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Chromosome
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia