title: Silver positivity of the NORs during embryonic development of Xenopus laevis.
abstract: Transcriptional activity of ribosomal RNA (rRNA) genes is detectable around blastula-gastrula transition during the embryonic development of amphibians and other non-mammalian systems. The silver staining reaction, known to selectively stain transcriptionally active nucleolus organizer regions (NORs) both in interphase and metaphase chromosomes allowed us to follow the activation of the NORs during the embryonic development of Xenopus laevis.
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D002875:Chromosomes / Q000648:ultrastructure; D004625:Embryo, Nonmammalian / Q000648:ultrastructure*; D007399:Interphase; D008677:Metaphase; D009697:Nucleolus Organizer Region / Q000378:metabolism* / Q000648:ultrastructure; D012335:RNA, Ribosomal / Q000235:genetics*; D012835:Silver Nitrate; D013194:Staining and Labeling; D014158:Transcription, Genetic; D014982:Xenopus laevis
chemical_list: D012335:RNA, Ribosomal; D012835:Silver Nitrate