基于CRISPR/Cas9技术的水稻miR1866突变体构建

microRNA (miRNA)是长度为18～25个碱基的非编码单链RNA,在植物生长发育过程中起着重要的调节作用.水稻是世界上重要的粮食作物之一,近年来调控水稻生长发育的miRNA不断被发掘,但目前关于miR 1866的研究还比较少.本研究通过构建miR1866的CRISPR/Cas9表达载体,创制miR1866的突...     

团头鲂(Megahbrama amblycephala) Caspase 9 基因全长cDNA的克隆及在氨氮胁迫下的表达分析

为了解团头鲂(Megahbrama amblycephala) Caspase 9基因序列特征及其在氨氮胁迫过程中的作用,应用末端快速扩增(Rapid amplification of cDNA ends,RACE)技术克隆得到团头鲂Caspase 9基因全长1613 bp的cDNA序列,包括185 bp的5 '末端非翻译区(Untranslated regions,UTR)、96 bp的3'UTR、1332 bp的开放阅读框(Open Reading Frame,ORF).氨基酸多序列比对显示,平均同源性为77.74％,表明团头鲂Caspase9基因具有较高的保守性;系统进化分析显示,该基因氨基酸序列与其他鱼类Caspase 9聚为一支,并与锦鲤(Cyprinus carpio) Caspase 9亲缘关系较近;荧光定量PCR结果显示,Caspase 9基因在团头鲂各组织中均有表达,在脑中表达量最高,在肌肉中表达量最低,同时,在胁迫和恢复过程中,该基因在肝和脑中的表达规律相似,均在胁迫期间出现表达量上调,整体呈类似波浪形表达谱.研究结果表明,氨氮胁迫下,Caspase 9基因参与团头鲂的免疫防御,并与细胞凋亡分子过程有关.本研究结果可为进一步了解团头鲂应答氨氮胁迫分子机制提供理论依据.     

Use of differently enriched rotifers,Brachionus plicatilis,during larviculture of haddock,Melanogrammus aeglefinus: effects on early growth,survival and body lipid composition

We evaluated the effects of enriched rotifers on growth, survival and on the lipid composition of haddock larvae. The treatments tested were (1) AlgaMac 2000^®, (2) AquaGrow^® Advantage and (3) Pavlova sp. paste and AlgaMac 2000^®. The treatments did not influence larval growth rate throughout the experimental period (P = 0.70). Larvae from all treatments grew approximately 8% of their dry weight per day between 1 and 29 days post hatch (dph). Treatment 3 resulted in the best survival, estimated to be 3 on a scale from 0 to 5, whereas for the two other groups the survival estimates were 0 and 2. Rotifers from treatment 1 had low sterol concentrations, high eicosapentaenoic acid/arachidonic acid ratio and their feeding resulted in high larval mortality. Rotifers enriched with Pavlova sp. had the lowest proportions of the sum of saturated fatty acids, docosahexaenoic acid and sum of ω3 and the highest proportions of the sum of monounsaturated fatty acids (ΣMUFA). This was partially reflected in larvae from treatment 3 in that they had the highest proportions of ΣMUFA and the lowest proportions of Σω3 (P < 0.0001 for both analyses). In addition, these larvae had the highest and lowest ΣC₂₀ and ΣC₂₂ polyunsaturated fatty acids (PUFA) respectively (P < 0.0001 for both analyses). We suggest that more research with ω3 and ω6 PUFA can lead to improvements in the rearing of haddock larvae produced in hatcheries.     

The pond's shape matters: differential growth,physiological condition and survival of epibenthic Farfantepenaeus aztecus postlarvae

As a function of the water quality provided by square, circular and oval experimental ponds, the growth, survival and oxygen requirements in epibenthic postlarvae of Farfantepenaeus aztecus were analysed in relation to their routine metabolism and apparent heat increment. Temperature, oxygen concentration, pH and salinity were measured daily in two experimental ponds of each shape. The postlarvae oxygen consumption during two 24‐h cycles, their growth, physiological condition and survival and the productivity in the ponds were estimated. Low values of pH, oxygen concentration and phytobenthos productivity, and reduced postlarvae relative growth and survival were observed in the square ponds. We suggest that the latter results from a deficient water circulation related to the effect of the pond's shape on dissolved oxygen levels and, consequently, on growth and survival. The postlarvae routine metabolism, including feeding, varied between 1.91 and 2.25 mg O₂ h^?1 g^?1 wet weight, whereas the minimum oxygen concentration needed in the ponds is approximately 4.25 mg O₂ L^?1. These conditions were achieved in the oval ponds concurrent with higher survival and growth values, in which individuals distributed randomly, for which we suggest that oval‐shaped ponds could be the most adequate for the culture of this and other penaeid species.     

不锈钢管的焊接技术

汽轮机润滑油系统油管道焊接是汽轮机专业焊接的一个重点.为了保证汽轮杌润滑油管道系统的清洁度及汽轮机主机润滑系统、调节保安系统安全可靠地工作,其材质全部由不锈钢组成,所以油管道安装的内在质量格外重要.总结出一套焊接组装工艺措施,提高了生产效能,满足了汽轮机油管的质量要求.     

CRISPR/Cas9介导的多基因编辑系统在大豆中的应用

自CRISPR/Cas9(clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9)基因组编辑技术发现以来,迅速在作物中得到广泛应用.但是,CRISPR/Cas9多基因编辑系统在大豆中的研究尚待开发.本文利...     

水稻抽穗期基因OsDof6功能的初步研究

【目的】以前期通过穗发育芯片筛选到一个水稻Dof家族转录因子OsDof6为研究对象,进一步探究OsDof6的表达模式与生物学功能。【方法】对OsDof6的基因、蛋白及启动子序列进行生物信息学分析,利用CRISPR/Cas9技术对该基因进行定点编辑,通过实时定量PCR和亚细胞定位技术分析该基因的表达模式。【结果】对该基因的启动子序列分析表明,该基因启动子中存在大量与光响应、激素响应及胁迫响应相关的顺式调控元件。利用CRISPR/Cas9技术获得了2种不同突变类型的功能缺失突变体9522^Dof6-3和9522^Dof6-4。对突变体T₁株系进行表型观察发现,相较于对照,两种突变体在营养生长阶段分蘖数明显降低,转入生殖生长阶段后,两种突变体的抽穗时间推迟约3 d。实时定量PCR结果显示OsDof6在水稻根、茎、叶和穗中均有不同程度的表达,在穗发育后期相对表达量明显提高;通过亚细胞定位分析发现OsDof6定位于细胞核。【结论】初步判断OsDof6基因会影响水稻分蘖数与抽穗期。     

Use of two PGPR strains in the integrated management of blast disease in rice (Oryza sativa) in Southern Spain

Biocontrol capacity of two plant growth-promoting rhizobacteria (PGPR) strains, against blast disease in rice paddy fields in Southern Spain was studied in three cropping seasons. Both strains (Pseudomonas fluorescens Aur 6 and Chryseobacterium balustinum Aur 9) had already shown biocontrol capacity against pathogens, ability to induce systemic resistance against leaf pathogens and against salt stress in different plant species. Bacterial treatments were carried out on seeds and/or on leaves. Strains were inoculated individually and in combination. Protection against natural disease incidence was evaluated, and rice production and quality measured in 2005 and 2006 trials. In 2004, natural disease incidence was low (between 0.1% and 0.35% of damaged leaf surface) due to environmental conditions; under these conditions, both strains significantly protected plants against rice blast. In 2005, disease incidence was higher than in 2004, reaching higher values of affected leaf surface in controls. In these conditions, each strain individually protected rice against rice blast, although the combination of both strains was the most effective treatment. All three treatments (Aur 6, Aur 9 and Aur 6 + Aur 9) reached 50% protection in panicles, with Aur 9 being the most effective. In 2006, the most effective treatment was the combination of both strains on leaves in three physiological stages, suggesting a biocontrol mediated protection. On the other hand, when bacteria were applied to seeds, disease incidence decreased up to 50%, suggesting induction of systemic resistance. Finally, a direct relation between protection mediated by the PGPR and the increase in rice productivity (mT/ha) and quality (weight of 1000 seeds and number of intact grains after milling) was found.     

优质花生新品种唐花9号的选育及应用前景分析

唐花9号花生新品种,是唐山市农业科学研究院采用生物技术与常规技术相结合的方法,将优质与高产相结合,经过多年的单株定向选择,培育出的适合市场需求、符合外贸出口标准的花生新品种.2006年通过河北省鉴定.     

圆斑星鲽sox9基因的克隆与表达

本研究筛选到圆斑星鲽(Verasper variegatus)的性别相关基因sox9,并通过RACE技术获得了全长序列,基因全长为3287 bp,包括1431 bp的ORF,编码477个氨基酸,368 bp的5¢ UTR和1488 bp的3¢ UTR。在3¢ UTR中有多聚腺苷酸尾和加尾信号AATAAA。通过荧光定量PCR测定了sox9基因在圆斑星鲽成鱼不同组织中的表达水平,发现sox9基因在圆斑星鲽的脑、眼、鳃、心、肝、胆、肠、精巢、卵巢、肾和肌肉等各个组织中都有不同程度的表达。在鳃、脑和精巢组织中检测到较高水平的sox9转录,其中精巢中的转录水平显著高于其他组织,sox9基因在性腺中的表达显示出性别两相性差异。其在精巢中的表达水平要显著高于卵巢,说明sox9基因与雄性性腺发育相关。通过测定sox9基因在圆斑星鲽幼鱼不同发育时期(20、30、40、50、60、70和80日龄)的表达水平,发现其在20~50日龄表达量逐渐下降,在60日龄时表达量上升,推测表达量上升可能与幼鱼性腺分化相关。