References of "Jennane, A"
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See detailFate of the nucleolar vacuole during resumption of cell cycle in pea cotyledonary buds
Jennane, A.; Thiry, Marc ULg; Diouri, M. et al

in Protoplasma (2000), 210(3-4), 172-178

Meristematic cells of pea cotyledonary buds blocked in G(0-1) state contain a small nucleolus with a large central clear area surrounded by a fibrillar rim. The nucleolar structure varies according to the ... [more ▼]

Meristematic cells of pea cotyledonary buds blocked in G(0-1) state contain a small nucleolus with a large central clear area surrounded by a fibrillar rim. The nucleolar structure varies according to the cell cycle from the G(0-1)-blocked state until the first mitoses occurring between 24 and 27 h after removal of the main stem. In order to better identify and understand the role of the central area in the nucleolar function, its content was investigated by cytochemical and terminal deoxynucleotidyl transferase-immunogold methods. The central area showed the characteristics of a vacuole commonly constituted of the condensed chromatin, ribonucleoprotein granules, and lack of argyrophilic proteins. 3 h alter decapitation, a thickening of the fibrillar rim occurred, accompanied by an increase of granules in the vacuole. After 6 h, the unique vacuole broke up into two to four small vacuoles in which the granules are more abundant. After 12 h the nucleolus acquired compact structure with few minute vacuoles dispersed over the fibrillar component. During the whole cell cycle, the condensed chromatin is always observed in the vacuole. Our findings suggest that the appearance of the vacuoles is subsequent to the output of preribosomes from nucleolus. These vacuoles might play a role in condensation and decondensation of the chromatin. [less ▲]

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See detailIdentification of coiled body-like structures in meristematic cells of Pisum sativum cotyledonary buds.
Jennane, A.; Thiry, Marc ULg; Goessens, Guy ULg

in Chromosoma (1999), 108(2), 132-42

This study focused on two types of nuclear bodies visible in plant cells that were previously thought to be similar to the coiled bodies (CBs) of animal cells: the nucleolus-associated body (NAB) and ... [more ▼]

This study focused on two types of nuclear bodies visible in plant cells that were previously thought to be similar to the coiled bodies (CBs) of animal cells: the nucleolus-associated body (NAB) and dense body (DB). We show that both NABs and DBs share common features with animal CBs: they consist of ribonucleoproteins, are silver-stainable, and lack DNA. Immunoelectron microscopy shows that only the NABs are rich in snRNAs and fibrillarin, two markers characteristic of animal CBs. This suggests that NABs rather than DBs are the plant counterparts of the CBs of animal cells. These structures appear most frequently in cells blocked in G0-1, their frequency gradually declining with resumption of the cell cycle and nucleolar activity. During this reactivation period, NABs are released from the nucleolus to the nucleoplasm, suggesting that they may act as nuclear transport or sorting structures. [less ▲]

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See detailNucleolus-associated bodies in meristematic cells of Pisum sativum
Jennane, A; Thiry, Marc ULg; Goessens, G

in Cell Biology International (1998), 22

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See detailUltrastructural distribution of DNA within plant meristematic cell nucleoli during activation and the subsequent inactivation by a cold stress.
Mineur, Pierre ULg; Jennane, A.; Thiry, Marc ULg et al

in Journal of Structural Biology (1998), 123(3), 199-210

We have investigated the precise location of DNA within the meristematic cell nucleolus of Zea mays root cells and Pisum sativum cotyledonary buds, in the course of their activation and induced ... [more ▼]

We have investigated the precise location of DNA within the meristematic cell nucleolus of Zea mays root cells and Pisum sativum cotyledonary buds, in the course of their activation and induced inactivation following a subsequent treatment at low temperature. For this purpose, we combined the acetylation method, providing an excellent distinction between the various nucleolar components, with the in situ terminal deoxynucleotidyl transferase-immunogold technique, a highly sensitive method for detecting DNA at the ultrastructural level. In addition to the presence of DNA in the condensed chromatin associated with the nucleolus, we demonstrated that a significant label was detected in the nucleolus of quiescent cells in both plant models. Evident labels were also found in the dense fibrillar component of actived nucleoli. Whereas in inactivated nucleoli no significant label was observed within the dense fibrillar component, an intense label was seen over the large heterogeneous fibrillar centres only during inactivation. The granular component was never significantly labelled. These results appear to indicate that the DNA present in the dense fibrillar component of activated nucleoli withdraws from this structure during its inactivation and becomes incorporated in the large fibrillar centres. These observations suggest that in plant cells inactivation of rRNA genes is clearly accompanied by changes in the conformation of ribosomal chromatin. [less ▲]

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