Structural components of the nuclear body in nuclei of Allium cepa cells.
Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and function are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 microm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level confirmed that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.
Tao
W
W
College of Life Sciences, Peking University, Beijing, China.
Yan
C H
CH
Cai
T
T
Hao
S
S
Zhai
Z H
ZH
D002466:Cell Nucleolus / Q000378:metabolism / Q000648:ultrastructure; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure*; D004247:DNA / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D007399:Interphase / Q000502:physiology; D008854:Microscopy, Electron; D019697:Onions / Q000378:metabolism / Q000648:ultrastructure*; D018514:Plant Structures / Q000378:metabolism / Q000648:ultrastructure*; D035463:Pol1 Transcription Initiation Complex Proteins; D012333:RNA, Messenger / Q000378:metabolism / Q000648:ultrastructure; D012261:Ribonucleoproteins / Q000378:metabolism / Q000648:ultrastructure; D016622:Silver Staining; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D014157:Transcription Factors; C063844:transcription factor UBF; D004247:DNA