Biomaterial Database

Electron microscopic in situ hybridization in amphibian lampbrush chromosomes. 1993

M L Bonnanfant-Jaïs, and M Penrad-Mobayed, and N Angelier

Centre de Biologie Cellulaire, Ivry-sur-Seine/France.

Electron microscopy RNA/RNA in situ hybridization was adjusted to Pleurodeles lampbrush chromosomes. The cRNA probe used was synthesized from genomic DNA sequences which were proven to be moderately repetitive. Preembedding hybridization was performed on lampbrush chromosome preparations, and several fixation and hybridization conditions were tested. Paraformaldehyde and glutaraldehyde were used as fixatives at various concentrations and durations. Hybridization was then performed with or without formamide for various times of incubation. The best results were obtained when hybridization was carried out for 4 h at 42 degrees C in the presence of formamide, with lampbrush chromosomes having been previously fixed overnight in a mixture of paraformaldehyde/glutaraldehyde. Due to the excellent preservation of the ultrastructure and specificity of the signal obtained under these conditions, we were able to demonstrate, at the ultrastructural level, that such RNA expression occurs in two types of lampbrush loop ribonucleoprotein matrices showing a different morphology of their transcripts. Furthermore, a different mapping of the same sequence along the loop DNA axes is strongly suggested by a different labeling distribution in these loops.

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
D010999	Pleurodeles	A genus of aquatic newts belonging to the family Salamandridae and sometimes referred to as "spiny" tritons. There are two species P. waltlii and P. poireti. P. waltlii is commonly used in the laboratory. Since this genus adapts to aquarium living, it is easy to maintain in laboratories.	Pleurodele
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
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
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription
D015347	RNA Probes	RNA, usually prepared by transcription from cloned DNA, which complements a specific mRNA or DNA and is generally used for studies of virus genes, distribution of specific RNA in tissues and cells, integration of viral DNA into genomes, transcription, etc. Whereas DNA PROBES are preferred for use at a more macroscopic level for detection of the presence of DNA/RNA from specific species or subspecies, RNA probes are preferred for genetic studies. Conventional labels for the RNA probe include radioisotope labels 32P and 125I and the chemical label biotin. RNA probes may be further divided by category into plus-sense RNA probes, minus-sense RNA probes, and antisense RNA probes.	Gene Probes, RNA,RNA Probe,Probe, RNA,Probes, RNA,Probes, RNA Gene,RNA Gene Probes
D017403	In Situ Hybridization	A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.	Hybridization in Situ,Hybridization, In Situ,Hybridizations, In Situ,In Situ Hybridizations
D018075	RNA, Complementary	Synthetic transcripts of a specific DNA molecule or fragment, made by an in vitro transcription system. This cRNA can be labeled with radioactive uracil and then used as a probe. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Complementary RNA,cRNA,cRNA Probes,Probes, cRNA