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1.
2.
C Batini J M Billard 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1984,299(12):521-524
The spontaneous discharge frequency of Purkinje cells and neurones of the cerebellar nuclei was evaluated in rats after complete bilateral destruction of their inferior olive with 3-acetylpyridine, performed one day to six months before. The deafferentation from the climbing fibers produced an increased inhibitory action of the Purkinje cells on their target neurones, lasting at least for one week. A relative compensation took place progressively during the first month, but the normal activity of the circuit did not recover even after six months. 相似文献
3.
A stereotaxic apparatus and technique for its implantation in diencephalic nuclei of Atlantic salmon parr of 20 to 30 g body weight is described. An atlas of nuclei in the diencephalon is also presented. 相似文献
4.
Bacteria indicating faecal contamination, cell-culturable enteroviruses and hepatitis A virus (HAV) were investigated in sea-water and in mussels exposed in an unpolluted marine environment, over a 7-month period with two samplings per month. Of the 16 mussel samples examined, none contained cell-culturable enteroviruses, four showed a low-level contamination by HAV and two did not conform to the current bacteriological norms. No connection was observed between the viral and bacterial contamination. No viral contamination was detected in the sea-water samples, but two gave bacterial counts above current norms. 相似文献
5.
Independent carrot (Daucus carota) hairy root lines were established by inoculation of discs taken from the same carrot with Agrobacterium rhizogenes 8196 and A. tumefaciens C58C1(pRi8196) carrying pRi8196. Several lines were compared with respect to T-DNA length. One of them was found to have integrated sequences covering more than 50 kbp of the Ri plasmid 相似文献
6.
Peter Bramley Chantal Teulieres Ian Blain Colin Bird Wolfgang Schuch 《The Plant journal : for cell and molecular biology》1992,2(3):343-349
Transgenic tomato plants expressing antisense RNA to a ripening-related cDNA clone (pTOM5) had yellow ripening fruit and pale coloured flowers. Carotenoid levels in fruit of these plants were reduced by up to 97%. In order to determine the step of carotenoid biosynthesis which was blocked, a cell-free system active in the synthesis of carotenoid intermediates was prepared. Incubations with radiolabelled carotenoid precursors led to the identification of the block between GGDP and phytoene. Analysis of carotenoids in different tissues of transgenic and control plants indicated that although ripe fruit and flower carotenoid levels were reduced in the modified plants, leaf carotenoid levels were not decreased. This implies that the pTOM5 gene product is not involved in carotenoid synthesis in the leaf. 相似文献
7.
Spermiogenesis in the rainbow trout (Salmo gairdneri) 总被引:2,自引:0,他引:2
Dr. Roland Billard 《Cell and tissue research》1983,233(2):265-284
In an ultrastructural study on the spermiogenesis of the rainbow trout (Salmo gairdneri R.) four spermatogenetic stages were identified. In young round spermatids, the nuclear chromatin was first heterogeneous (euchromatin and heterochromatin). Subsequently, it became more homogeneous and started to condense in the form of coarse granules and fibers and then into fibrils associated in ribbon-like elements which eventually partly fused together. During early spermiogenesis, a juxtanuclear vacuole appeared in the area where the nuclear envelope was specialized due to condensation of material between the two envelopes and a slight accumulation of nuclear material. This area was finally located in the anterior part of spermatids and spermatozoa; it probably plays a role during fertilization. A flagellar rootlet appeared early in spermiogenesis; it may play a role in the attachment of the flagellum to the nucleus since it persisted until the centriolar complex was definitively fixed in the implantation fossa. The flagellum did not display a plasma membrane and was first located in the cytoplasm, but when it was later extruded from the cell, it acquired a membrane. The cytoplasm was rich in ribosomes (free or in small groups) but poor in membranous organelles. The few mitochondria polarized around the centriolar complex were finally organized into an annular mid-piece. The spermatids remained connected by intercellular bridges until the end of spermiogenesis. The complexity of trout spermiogenesis is intermediate between that in poecilids and that in carp and pike, which have very simple spermatozoa. The role of the material from the nucleus and the cytoplasm reaching the Sertoli cell in the control of spermatogenesis has been discussed. 相似文献
8.
Véronique Guellec Chantal David Michel Branchard Jacques Tempé 《Plant Cell, Tissue and Organ Culture》1990,20(3):211-215
Genetically transformed grapevine (Vitis vinifera L.) roots were obtained after inocultation of in vitro grown whole plants (cv. Grenache) with Agrobacterium rhizogenes. The strain used contains two plasmids: the wild-type Ri plasmid pRi 15834 and a Ti-derived plasmid which carries a chimaeric neomycin phosphotrans-ferase gene (NPT II) and the nopaline synthase gene. Expression of the NPT II gene can confer kanamycin resistance to transformed plant cells. Slowly growing axenic root cultures derived from single root tips were obtained. Opine analysis indicated the presence of agropine and/or nopaline in established root cultures. For one culture, the presence of T-DNA was confirmed by dot-blot hybridization with pRi 15834 TL-DNA. Callogenesis was induced by subculturing root fragments on medium supplemented with benzylaminopurine and indoleacetic acid.Transformation of in vitro cultured grapevine cells has recently been reported (baribault T.J. et al., Plant Cell Rep (1989) 8: 137–140). In contrast with the results presented here, expession of the NPT II gene Conferred kanamycin resistance to Vitis vinifera calli that was sufficient for selection of trasformed cells.Abbreviations BAP
benzylaminopurine
- IAA
indoleacetic acid
- NAA
naphtaleneacetic acid
- NPT II
neomycin phosphostransferase II
- EDTA
ethylenediaminetetraacetic acid 相似文献
9.
C. Kevers B. Bisbis F. Le Dily J. P. Billard C. Huault Th. Gaspar 《In vitro cellular & developmental biology. Plant》1995,31(2):122-126
The transfer of light-cultured green normal (N) and white habituated (HNO) sugarbeet callus to darkness reduced the growth
of N callus and improved growth and delayed necrosis in the HNO callus. The decrease of dry matter of N callus under darkness
was accompanied by a reduced content of carotenoids and by decreased CO2 fixation, which was compensated by an increased dependency on externally supplied sucrose. The levels of some organic nitrogen
compounds such as glutamate, proline, and free polyamines were not affected by transfer to darkness of N or HNO callus. Darkness
decreased ethylene emissions in both callus types. In the HNO callus, the sucrose growth dependency and the CO2 fixation were unaffected by darkness. Chlorophylls were absent both in light and darkness, whereas some carotenoids were
accumulated in the HNO callus only in dark conditions. In another connection, a significant increase of peroxidase activity,
which did not occur in the N callus, was induced by darkness in the HNO callus. A decreased content of thio-barbituric acid
(TBA)-reactive substances was measured in the HNO callus transferred to darkness, whereas an increase was noticed in the N
callus placed in the same conditions. These metabolic changes and the reduction of cellular damage in darkness revealed light-induced
stress reactions leading to necrosis and to reduced growth of HNO callus. It appeared that darkness allowed the HNO callus
to avoid the photooxidation stress. Therefore, the favorable effect of darkness on HNO growth might be explained by the suppression
of photooxidative damage due to the absence of carotenoids. The higher peroxidase activity in the HNO callus maintained in
darkness raised the problem of heme synthesis in this heterotrophic callus. 相似文献
10.