title: [Transcription complexes with nucleolar and chromosomal origins in oocytes of Pleurodeles waltlii and P. poireti (amphibia, urodela) (author's transl)].
abstract: The method of spreading transcription complexes has been applied to amphibian oocytes of Pleurodeles genus. Complexes of nucleolar origin show a regular and homogeneous organization similar to that described in other materials. The observations add to the interpretation as an amplification of nucleolar DNA and a redundancy of ribosomal cistrons in the two species studied. -- On the other hand, complexes of chromosomal origin display a great diversity. Two main characteristics can be drawn: the existence of several transcription units in a chromosomal organization unit and the possibility to point out a special architecture at the RNP fibril level. Applying a shadowing technique used for isolated molecules is an improvement compared with earlier methods based on PTA coloration.
mesh_terms: D000663:Amphibians / Q000033:anatomy & histology*; D000818:Animals; D002466:Cell Nucleolus; D002875:Chromosomes; D004247:DNA; D005260:Female; D008854:Microscopy, Electron; D009865:Oocytes; D010063:Ovum; D012270:Ribosomes; D013045:Species Specificity; D014158:Transcription, Genetic
chemical_list: D004247:DNA
vernacular_title: Complexes de transcription d'origines nucléolaire et chromosomique d'ovocytes de Pleurodeles waltlii et P. poireti (amphibiens, urodèles)