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 3H uridine; later it becomes more and more electron‐dense so in follicles of 400 μm in diameter its components and 3H 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
The nucleolus and its modifications during oogenesis of Torpedo marmorata / Prisco, Marina; Ricchiari, Loredana; Montella, R; Liguoro, Annamaria; Andreuccetti, Piero. - In: JOURNAL OF FISH BIOLOGY. - ISSN 0022-1112. - STAMPA. - 65:(2004), pp. 1489-1497.
The nucleolus and its modifications during oogenesis of Torpedo marmorata
PRISCO, MARINA;RICCHIARI, LOREDANA;LIGUORO, ANNAMARIA;ANDREUCCETTI, PIERO
2004
Abstract
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 3H uridine; later it becomes more and more electron‐dense so in follicles of 400 μm in diameter its components and 3H 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 granulosaI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
