DNA methylation and histone acetylation: genotypic variations in hybrid poplars, impact of water deficit and relationships with productivity     

Delphine Gourcilleau  Marie-Béatrice Bogeat-Triboulot  Didier Le Thiec  Clément Lafon-Placette  Alain Delaunay  Walid Abu El-Soud  Franck Brignolas  Stéphane Maury 《Annals of Forest Science》2010,67(2):208-208

? Several reports on annual plants have already shown the involvement of epigenetic modifiers such as DNA methylation in their adaptation to abiotic stresses.

? Nevertheless, the genotypic variations of epigenetic modifiers, their possible correlations with morphological traits and the impact of water deficit have not been described for perennial plants.

? Six genotypes of Populus deltoides × P. nigra were subjected or not to a moderate water deficit treatment. Various morphological traits such as the height of the plants, their biomass and the total leaf area were measured to characterize the productivity in both conditions. Levels of DNA methylation, histone acetylation and the activities and isoform accumulation of the corresponding enzymes were measured at the shoot apex, the site of morphogenesis. Genotypic variation was observed for the morphological traits and the epigenetic variables and correlations were established among them. Genotypic variation for DNA methylation was detected in hybrid poplars. A positive correlation was demonstrated between DNA methylation percentage and productivity under well watered conditions.

? While there was a general decrease of growth for all genotypes in response to a moderate water deficit, genotypic dependant variations of DNA methylation were found suggesting different strategies among hybrids.

  相似文献   

SPINAL SUB ARACHNOID CYSTS IN 13 DOGS     

Kirsten  Gnirs  DVM  Yannick  Ruel  DVM  Stephane  Blot  DVM  PHD  Dominique  Begon  DVM  Delphine  Rault  DVM  Fran&#;loise  Delisle  DVM  Lilia  Boulouha  DVM  Marie-anne  Colle  DVM  Claude  Carozzo  DVM  Pierre  Moissonnier  DVM  PHD 《Veterinary radiology & ultrasound》2003,44(4):402-408

Thirteen dogs, including 6 Rottweiler dogs, exhibiting clinical signs of spinal cord dysfunction and myelographically confirmed subarachnoid space enlargement were investigated. To characterize the lesions and to get a better understanding of their pathogenesis, different imaging techniques were used in association with explorative surgical procedures (12 dogs) and histopathologic techniques (5 dogs). All subjects underwent preoperative myelography, five of which were examined by computed tomography (CT) scanning and one by magnetic resonance imaging (MRI) as well as cerebrospinal fluid (CSF) flow measurement (velocimetry). Most animals were <12 months old (7/13 dogs) and Rottweilers were over-represented (6/13 dogs). The lesions were mainly located dorsally with respect to the spinal cord (10/13 dogs) and in the cranial cervical area (8/13 dogs). MRI suggested spinal cord deviation with signs of ventral leptomeningeal adhesion opposite the enlarged space. In one dog, velocimetry confirmed that the "cyst" was freely communicating with the surrounding CSF space. Surgical investigation confirmed leptomeninges-induced ventral adhesion in 4/5 dogs. Follow-up studies, carried out from 6 months to 2.5 years postoperatively, showed there was full recovery in 8/13 dogs. This study suggests that the compression of the spinal cord is possibly not caused by a cyst. Adhesion resulting from a combination of microtrauma and chronic inflammatory processes induces a secondary enlargement of the subarachnoid space and may be a significant causative factor in spinal cord compression and dysfunction. The over-representation of Rottweilers and the young age of the animals in the study suggest a possible genetic predisposition and an inherited etiology.  相似文献   

欧洲仔猪氨基酸营养——仔猪低蛋白质高生长性能的氨基酸平衡日粮     

陈春梅 《饲料与畜牧》2007,(8):17-18

与中国仔猪的断奶日龄相似，欧洲仔猪的平均断奶日龄为21d～28d。仔猪阶段的饲料通常分为3个阶段：（1）教槽料：通常是哺乳仔猪在母猪的引导下采食；（2）开食前的饲料：一般在20日龄时，体重达7kg的小猪，一直采食开食前料直到体重达15kg；（3）开食料：一般小猪断奶后20～50日龄期间采食，体重从15kg到30kg。在法国，平均每头母猪年产仔猪数达20头，采用这种饲养方案的仔猪，  相似文献   

Assessment of impulse duration thresholds for electrical stimulation of muscles (chronaxy) in dogs     

Sawaya SG  Combet D  Chanoit G  Thiebault JJ  Levine D  Marcellin-Little DJ 《American journal of veterinary research》2008,69(10):1305-1309

OBJECTIVE: To determine the electrical impulse duration thresholds (chronaxy) for maximal motor contraction of various muscles without stimulation of pain fibers in dogs. ANIMALS: 10 healthy adult Beagles. PROCEDURES: The dogs were used to assess the minimal intensity (rheobase) required to elicit motor contraction of 11 muscles (5 in the forelimb [supraspinatus, infraspinatus, deltoideus, lateral head of the triceps brachii, and extensor carpi radialis], 5 in the hind limb [gluteus medius, biceps femoris, semitendinosus, vastus lateralis, and tibialis cranialis], and the erector spinae). The rheobase was used to determine the chronaxy for each of the 11 muscles in the 10 dogs; chronaxy values were compared with those reported for the corresponding muscles in humans. RESULTS: Compared with values in humans, chronaxy values for stimulation of AA motor fibers in the biceps femoris and semitendinosus muscles and muscles of the more distal portions of limbs were lower in dogs. For the other muscles evaluated, chronaxy values did not differ between dogs and humans. CONCLUSIONS AND CLINICAL RELEVANCE: Application of the dog-specific chronaxy values when performing electrical stimulation for strengthening muscles or providing pain relief is likely to minimize the pain perceived during treatment in dogs.  相似文献   

Ostreid herpesvirus type 1 replication and host response in adult Pacific oysters,Crassostrea gigas     

Amélie Segarra  Laury Baillon  Delphine Tourbiez  Abdellah Benabdelmouna  Nicole Faury  Nathalie Bourgougnon  Tristan Renault 《Veterinary research》2014,45(1)

  相似文献   

塔乌库姆冰草肌动蛋白基因片段的克隆及序列分析     

李莉  贾纳提  张金林 《草原与草坪》2014,(5):6-10

根据其他植物Actin基因的保守序列设计一对简引并性物,以塔乌库姆冰草叶片总RNA为模板,采用RT-PCR的方法扩增出Actin基因片段并连接到载体上,阳性克隆经PCR检测后进行测序。结果表明：该片段长约600bp,编码199个氨基酸,所得序列与GenBank中注册的其他植物Actin基因序列同源性均在81%以上,与其他肌动蛋白的氨基酸序列同源性达88%。  相似文献   

Relationship between procyanidin and flavor contents of cocoa liquors from different origins     

Counet C  Ouwerx C  Rosoux D  Collin S 《Journal of agricultural and food chemistry》2004,52(20):6243-6249

The flavor of eight cocoa liquors of different origins (Africa, America, and Asia) and different varieties (Fine grades: criollo, trinitario, and nacional. Bulk-basic grade: forastero.) was analyzed by headspace solid-phase microextraction mass spectrometry (HS-SPME-MS). Their procyanidin contents were quantified by HPLC-UV (280 nm). Fine varieties with short fermentation processes proved to contain more procyanidins, while criollo from New Guinea and forastero beans showed the highest aroma levels. The levels of cocoa aroma compounds formed during roasting are shown to vary directly with bean fermentation time and inversely with residual procyanidin content in cocoa liquor. Measurement of antioxidant activity in cocoa liquor proved to be a useful tool for assessing residual polyphenols.  相似文献   

Rapid, low cost thin-layer chromatographic screening method for the detection of ochratoxin A in green coffee at a control level of 10 microg/kg.     

Alain Pittet  Delphine Royer 《Journal of agricultural and food chemistry》2002,50(2):243-247

A thin-layer chromatographic (TLC) screening method was developed for the detection of ochratoxin A (OTA) in green coffee at a control level of 10 microg/kg. The method is based on extraction of OTA with a mixture of phosphoric acid and dichloromethane, purification by liquid-liquid partition into sodium hydrogen carbonate, separation by normal-phase TLC, and detection by visual estimation of fluorescence intensity under a UV lamp at 366 nm. The method was validated by performing replicate analyses of uncontaminated green coffee material spiked at 3 different levels of OTA (5, 10, and 20 microg/kg), and also by comparing results obtained on a series of test trial green coffees naturally contaminated with OTA (range 0.2 to 136.7 microg/kg) with those measured by a quantitative immunoaffinity/HPLC method. The agreement between the two methods was excellent, and neither false positive nor false negative results were recorded. This screening method is rapid, simple, robust, and very cheap, which makes it particularly well adapted for implementation in coffee-producing countries.  相似文献   

Biomass harvesting from buffer strips in Italy: three options compared     

Raffaele Spinelli  Carla Nati  Natascia Magagnotti 《Agroforestry Systems》2006,68(2):113-121

There is an urgent need for new, mechanized systems that may restitute some profitability to buffer strip harvesting and motivate regular maintenance. An opportunity for innovation is offered by the growing success of chip-fed boilers, since the production of chips is simpler than that of logs and has a higher potential for cost reduction. Within this context, a study was conducted in Italy with the goals of: (a) designing three alternative chip harvesting methods for buffer strips, (b) field-testing the performance of each alternative, and (c) developing a model for estimating the cost of these methods under varying operational and economic conditions. The three harvesting methods reflected different mechanization levels, with escalating investment requirements. Overall, the study demonstrated that frequent maintenance of young, single row buffer strips generates profits only when thoroughly mechanized. Using a dedicated feller-buncher, a front-end loader for extraction and an industrial truck-mounted chipper brought the delivered cost below the 14 €/m³ loose chips (approximately 4 €/GJ) presently paid by the district heating stations. However, the intermediate-mechanization system showed the highest potential for improvements. The␣study generated a spreadsheet-based model for predicting the effects of varying work conditions and cost hypotheses.  相似文献   

Supernova shock breakout from a red supergiant     

Schawinski K  Justham S  Wolf C  Podsiadlowski P  Sullivan M  Steenbrugge KC  Bell T  Röser HJ  Walker ES  Astier P  Balam D  Balland C  Carlberg R  Conley A  Fouchez D  Guy J  Hardin D  Hook I  Howell DA  Pain R  Perrett K  Pritchet C  Regnault N  Yi SK 《Science (New York, N.Y.)》2008,321(5886):223-226

Massive stars undergo a violent death when the supply of nuclear fuel in their cores is exhausted, resulting in a catastrophic "core-collapse" supernova. Such events are usually only detected at least a few days after the star has exploded. Observations of the supernova SNLS-04D2dc with the Galaxy Evolution Explorer space telescope reveal a radiative precursor from the supernova shock before the shock reached the surface of the star and show the initial expansion of the star at the beginning of the explosion. Theoretical models of the ultraviolet light curve confirm that the progenitor was a red supergiant, as expected for this type of supernova. These observations provide a way to probe the physics of core-collapse supernovae and the internal structures of their progenitor stars.  相似文献