title: Electron microscopic observations of heterogeneous nuclear RNA of chicken reticulocytes.
abstract: Secondary structures of annealed, snapped-back and untreated chicken reticulocyte poly(A)-containing nuclear RNA were investigated by electron microscopy. Three shapes of molecules were observed: 'coat'hanger' shaped, loop-bearing and filamentous molecules. The former two shaped molecules consist of a small and large fold-back or loop plus a short hook or tail, corresponding to the poly(A) segment at the apparent middle of the structure. The third shaped molecule, mainly seen after snap-back treatment, possesses a small fold-back structure at one end only. It is suggested that the small and large fold-backs or loops of the molecule represent the 5'- and 3'-terminal hairpin structures, respectively. Two distinct sizes of molecule, small and large, irrespective of molecule shape, were observed.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000032:analysis; D002645:Chickens / Q000097:blood*; D006037:Glyoxal; D006358:Hot Temperature; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D011061:Poly A / Q000097:blood*; D012313:RNA / Q000097:blood*; D012332:RNA, Heterogeneous Nuclear / Q000097:blood*; D012333:RNA, Messenger; D012156:Reticulocytes / Q000032:analysis* / Q000166:cytology
chemical_list: D012332:RNA, Heterogeneous Nuclear; D012333:RNA, Messenger; D011061:Poly A; D006037:Glyoxal; D012313:RNA