title: Chromatin ultrastructure of lower vertebrates.
abstract: Meiotic and mitotic chromosomes from amphibians and snakes were studied by electron microscopy. By using water spreading, preceded by a mild NaCl pretreatment, we showed: 1. 'Beads on a string' arrangement of the chromatin fibres; 2. The presence of loops at pachytene chromomeres as well as during metaphase of both mitosis and first meiosis; 3. Transcriptional activity for non-ribosomal RNA on peripheral loops during the middle pachytene.
mesh_terms: D000818:Animals; D001001:Anura / Q000235:genetics*; D002843:Chromatin / Q000648:ultrastructure*; D066298:In Vitro Techniques; D008297:Male; D008540:Meiosis; D008854:Microscopy, Electron; D008938:Mitosis; D012671:Seminiferous Tubules / Q000648:ultrastructure; D012911:Snakes / Q000235:genetics*
chemical_list: D002843:Chromatin