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The nucleolus and its modifications during oogenesis of Torpedo marmorata
Author(s) -
Prisco M.,
Ricchiari L.,
Montella R.,
Liguoro A.,
Andreuccetti P.
Publication year - 2004
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.0022-1112.2004.00539.x
Subject(s) - nucleolus , biology , oogenesis , oocyte , ribosomal rna , microbiology and biotechnology , torpedo , nucleolus organizer region , anatomy , zoology , genetics , nucleus , embryo , gene , acetylcholine receptor , receptor
The structural organisation of the nucleolar apparatus during oogenesis of the spotted ray Torpedo marmorata was investigated. The observations showed that unlike other cartilaginous fishes, in T. marmorata the nucleolar apparatus was always represented by one or two conspicuous nucleoli, whose organization significantly changed during oocyte development. In the smallest follicles (follicles <300 μm in diameter) the nucleolus was made up of granular and fibrillar components, and actively incorporated 3 H uridine; later it becomes more and more electron‐dense so in follicles of 400 μm in diameter its components and 3 H uridine incorporation were no longer evident. These results indicate that in T. marmorata the nucleolar apparatus significantly changes and undergoes a possible impairment in rRNA synthesis. After nucleolus inactivation, the synthesis of rRNA may be substained by granulosa.