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51.
Natasha Spadafora Lara Perrotta Jeroen Nieuwland Diego Albani M. Beatrice Bitonti Robert J. Herbert John H. Doonan Angela M. Marchbank Ilario Siciliano Anne Lentz Gr?nlund Dennis Francis Hilary J. Rogers 《Annals of botany》2012,110(8):1631-1639
Background and Aims
How plant cell-cycle genes interface with development is unclear. Preliminary evidence from our laboratory suggested that over-expression of the cell cycle checkpoint gene, WEE1, repressed growth and development. Here the hypothesis is tested that the level of WEE1 has a dosage effect on growth and development in Arabidospis thaliana. To do this, a comparison was made of the development of gain- and loss-of-function WEE1 arabidopsis lines both in vivo and in vitro.Methods
Hypocotyl explants from an over-expressing Arath;WEE1 line (WEE1oe), two T-DNA insertion lines (wee1-1 and wee1-4) and wild type (WT) were cultured on two-way combinations of kinetin and naphthyl acetic acid. Root growth and meristematic cell size were also examined.Key Results
Quantitative data indicated a repressive effect in WEE1oe and a significant increase in morphogenetic capacity in the two T-DNA insertion lines compared with WT. Compared with WT, WEE1oe seedlings exhibited a slower cell-doubling time in the root apical meristem and a shortened primary root, with fewer laterals, whereas there were no consistent differences in the insertion lines compared with WT. However, significantly fewer adventitious roots were recorded for WEE1oe and significantly more for the insertion mutant wee1-1. Compared with WT there was a significant increase in meristem cell size in WEE1oe for all three ground tissues but for wee1-1 only cortical cell size was reduced.Conclusions
There is a gene dosage effect of WEE1 on morphogenesis from hypocotyls both in vitro and in vivo. 相似文献52.
53.
Samson Mani Katarzyna Szymańska Cyrille Cuenin David Zaridze Karen Balassiano Sheila CS Lima Elena Matos Alexander Daudt Sergio Koifman Victor Wunsch Filho Ana MB Menezes Maria Paula Curado Gilles Ferro Thomas Vaissière Bakary S Sylla Massimo Tommasino Luis Felipe Ribeiro Pinto Paolo Boffetta Pierre Hainaut Paul Brennan Zdenko Herceg 《Epigenetics》2012,7(3):270-277
Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.Key words: DNA methylation, upper aerodigestive tract, cancer, risk factors, biomarkers 相似文献
54.
J. O'Grady MB ChB MRCP. S. Warrington MB BChir MA MRCP. M.J. Moti S. Bunting BSc. R. Flower BSc PhD. A.S.E. Fowle MD MRCP. E.A. Higgs BSc MSc. S. Moncada MD PhD. 《Prostaglandins & other lipid mediators》1980,19(2):319-332
Prostacyclin infused intravenously in human volunteers induces ex vivo inhibition of platelet aggregation, tachycardia and hypotension. The inhibition of platelet aggregation is obtained with slightly lower doses than those which exhibit cardiovascular effects.The cardiovascular effects disappeared within a few minutes after discontinuing the infusion of prostacyclin but the platelet effects were longer lasting.Prostacyclin did not have any effect on platelet count, platelet factor 3, accelerated partial thromboplastin time, prothrombin time, euglobulin clot lysis time, fibrinogen degradation products, blood glucose concentration or urine sodium potassium ratio. 相似文献
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58.
JS Agerholm O Andersen MB Almskou C Bendixen J Arnbjerg GP Aamand US Nielsen F Panitz AH Petersen 《Acta veterinaria Scandinavica》2004,45(3):133
To investigate the congenital complex vertebral malformation syndrome (CVM) in Holstein calves, two breeding studies were
performed including 262 and 363 cows, respectively. Cows were selected from the Danish Cattle Database based on pedigree and
insemination records. Selected cows were progeny of sires with an established heterozygous CVM genotype and pregnant after
insemination with semen from another sire with heterozygous CVM genotype. Following calving the breeders should state, if
the calf was normal and was requested to submit dead calves for necropsy. In both studies, significantly fewer CVM affected
calves than expected were obtained; a finding probably reflecting extensive intrauterine mortality in CVM affected foetuses.
The findings illustrate increased intrauterine mortality as a major potential bias in observational studies of inherited disorders. 相似文献
59.
Bitonti MB Cozza R Chiappetta A Giannino D Ruffini Castiglione M Dewitte W Mariotti D Van Onckelen H Innocenti AM 《Journal of experimental botany》2002,53(371):1047-1054
Chromatin organization, nuclear DNA methylation and endogenous zeatin localization were investigated in shoot apical meristems (SAM) during juvenile and adult phases of peach (Prunus persica (L.) Batsch). The aim was to examine the extent to which these parameters could discriminate the juvenile and adult SAMs. Seedlings (juvenile, cannot flower), basal shoots (called juvenile-like, because they exhibit juvenile macroscopic traits) and apical shoots (competent to form flowers) of adult plants were chosen. Nuclear chromatin exhibited chromocentres that were peripherally distributed in SAMs of juvenile and juvenile-like shoots, but were diffusely spread in those of adult shoots. These patterns coincided with a peripheral labelling of DNA methylation in juvenile and juvenile-like meristem nuclei versus a diffuse labelling pattern in adult meristem nuclei. During vegetative growth (from March to June), the level of nuclear DNA methylation was higher in adult meristems than in juvenile and juvenile-like ones. The immunolocalization of zeatin in juvenile SAM was in the subapical region, but adult meristems exhibited a widespread localization or a signal confined within the boundaries of the central zone. The extent to which the acquisition of a strongly zonated pattern of these parameters as markers of floral competence in adult SAMs is discussed. 相似文献
60.
Giannino D Mele G Cozza R Bruno L Testone G Ticconi C Frugis G Bitonti MB Innocenti AM Mariotti D 《Journal of experimental botany》2003,54(393):2623-2633