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Active ribosomal cistrons in plant nucleolus
Author(s) -
Ghosh S.,
Chakrabarti A.,
Chaudhuri S. K.
Publication year - 1993
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1006/cbir.1993.1137
Subject(s) - nucleolus , ribosomal rna , biology , rnase p , transcriptional activity , prophase , biophysics , microbiology and biotechnology , chemistry , genetics , gene , rna , gene expression , nucleus , meiosis
In onion root‐tip cell nucleoli some tapered cylindrical structures appear in the dense fibrillar component (DFC) after cycloheximide treatment. These structures resemble the "Christmas‐tree" like configurations which have been noted in spread preparations from the nucleoli. The similarities in their general appearance are strengthened by observations after RNase and pepsin digestions. The presence of such structures in the DFC of prophase nucleoli has also been demonstrated. These observations indicate the presence of active ribosomal cistrons in DFC of the nucleolus. It is proposed that nucleolar transcription becomes initiated in the DFC around the FC (fibrillar centres) and then these transcripts along with their axis move to the granular component (GC) for their processing. As such some of these structures were observed to penetrate into the GC.