[Electron microscopy research on the chromatin structure of dispersed lampbrush chromosomes in the hen]. 1988

E R Gaginskaia, and A G Tsvetkov

The lampbrush chromosomes from the late previtellogenic and early vitellogenic oocytes of adult hens were spread according to Miller's technique and examined in electron microscope. The nucleosomes in the threads of the non-transcribed chromatin are uniformly distributed, the spaces between the nucleosomes correspond by their length to the linker DNA. Nucleosomes are absent in the transcriptional units with high intensity transcription. In transcriptional units with moderate and weak transcription the nucleosomes are identified in the axial chromatin fibril between RNA-polymerase granules, the space between them varying. The compactization ratio of DNA (the number of DNA mkm in a 1 mkm chromatin fiber) in non-transcribed fibrils is equal to 2.1, in transcriptional units with moderate and weak activity it is 1.7, and in transcriptional units with intensive transcription it is close to 1. The DNA compaction ratio in lateral loops of lampbrushes is determined by the intensity of transcription. It is supposed that in the native state the inactive chromatin with uniform spacing of nucleosomes has a supernucleosomal structure, while the DNA compaction ratio in the transcribed sequences corresponds to that on Miller's spreads.

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
D009707 Nucleosomes The repeating structural units of chromatin, each consisting of approximately 200 base pairs of DNA wound around a protein core. This core is composed of the histones H2A, H2B, H3, and H4. Dinucleosomes,Polynucleosomes,Dinucleosome,Nucleosome,Polynucleosome
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
D002645 Chickens Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA. Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D002843 Chromatin The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell. Chromatins
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
D004247 DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005260 Female Females
D006651 Histocytochemistry Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods. Cytochemistry
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

Related Publications

E R Gaginskaia, and A G Tsvetkov
December 1969, Doklady Akademii nauk SSSR,
E R Gaginskaia, and A G Tsvetkov
December 1979, Journal of cell science,
E R Gaginskaia, and A G Tsvetkov
April 1998, Molecular biology of the cell,
E R Gaginskaia, and A G Tsvetkov
December 1965, National Cancer Institute monograph,
E R Gaginskaia, and A G Tsvetkov
January 1978, Methods in cell biology,
E R Gaginskaia, and A G Tsvetkov
January 1958, The Journal of biophysical and biochemical cytology,
E R Gaginskaia, and A G Tsvetkov
May 1998, Trends in cell biology,
E R Gaginskaia, and A G Tsvetkov
March 1942, Science (New York, N.Y.),
Copied contents to your clipboard!