鸡软骨细胞体外分离培养鉴定以及过表达miR-15a对软骨细胞的影响

为分析miR-15a在肉鸡不同组织中的表达情况,并探究过表达miR-15a对体外培养鸡软骨细胞的影响。本研究首先通过倒置显微镜观察、PCR、凝胶电泳和甲苯胺蓝染色对体外分离培养的软骨细胞进行鉴定。通过实时荧光定量PCR检测miR-15a在肢体内外翻畸形(valgus-varus deformity, VVD)组和健康组肉鸡中(各3只)各组织的表达量。之后通过CCK8和EDU方法分析软骨细胞过表达miR-15a后细胞增殖情况。软骨细胞转染miR-15a mimics后,通过qPCR检测软骨细胞的标志基因Collagen-2、Aggrecan、Collagen-10,成熟分化基因Runx2、Sox9、VEGF、MMP9,炎性因子IL-1β、IL-6、IL-8、IL-10、TNF-α、TGF-β3以及凋亡基因Fas、FasL、Bcl-2的表达量。并构建FKBP5 3'UTR的野生型载体和突变型载体,通过双荧光素酶检测报告检测miR-15a与FKBP5的靶向关系。结果表明,本研究所用的胰蛋白酶、Ⅱ型胶原酶和透明质酸酶联合消化法成功分离得到状态良好的软骨细胞。荧光定量结果显示,miR-15a在各组织中均有表达,与健康组相比,miR-15a在VVD组的肝(P < 0.01)、脾(P < 0.05)、胸腺(P < 0.01)中的表达量显著升高,在心和胸肌组织中的表达量显著降低(P < 0.01)。CCK8与EDU分析结果显示,与NC组相比,过表达miR-15a组软骨细胞增殖速度显著降低(P < 0.01),增殖细胞数量显著减少(P < 0.01)。qPCR结果显示,与mimics NC组相比,miR-15a mimics组的软骨细胞标志基因Aggrecan、成熟分化基因Sox9、Runx2表达量显著降低(P < 0.05),Fas基因表达量极显著上升(P < 0.01),FasL基因和抗凋亡基因Bcl-2极显著下降(P < 0.01)。成功构建了FKBP5 3'UTR野生型和突变型载体,双荧光素酶检测报告结果显示预测的靶基因FKBP5与miR-15a没有靶向关系。本研究成功分离并鉴定了鸡软骨细胞,过表达miR-15a抑制鸡软骨细胞增殖、成熟和分化并促进细胞凋亡。     

Major outer membrane proteins of Brucella spp.: past,present and future

The major outer membrane proteins (OMPs) of Brucella spp. were initially identified in the early 1980s and characterised as potential immunogenic and protective antigens. They were classified according to their apparent molecular mass as 36–38 kDa OMPs or group 2 porin proteins and 31–34 and 25–27 kDa OMPs which belong to the group 3 proteins. The genes encoding the group 2 porin proteins were identified in the late 1980s and consist of two genes, omp2a and omp2b, which are closely linked in the Brucella genome, and which share a great degree of identity (>85%). In the 1990s, two genes were identified coding for the group 3 proteins and were named omp25 and omp31. The predicted amino acid sequences of omp25 and omp31 share 34% identity. The recent release of the genome sequence of B. melitensis 16 M has revealed the presence of five additional gene products homologous to Omp25 and Omp31. The use of recombinant protein technology and monoclonal antibodies (MAbs) has shown that the major OMPs appear to be of little relevance as antigens in smooth (S) B. abortus or B. melitensis infections i.e. low or no protective activity in the mouse model of infection and low or no immunogenicity during host infection. However, group 3 proteins, in particular Omp31, appear as immunodominant antigen in the course of rough (R) B. ovis infection in rams and as important protective antigen in the B. ovis mouse model of infection. The major OMP genes display diversity and specific markers have been identified for Brucella species, biovars, and strains, including the recent marine mammal Brucella isolates for which new species names have been proposed. Recently, Omp25 has been shown to be involved in virulence of B. melitensis, B. abortus and B. ovis. Mutants lacking Omp25 are indeed attenuated in animal models of infection, and moreover provide levels of protection similar or better than currently used attenuated vaccine strain B. melitensis Rev.1. Therefore, these mutant strains appear interesting vaccine candidates for the future. The other group 3 proteins identified in the genome merit also further investigation related to the development of new vaccines.     

不同生育阶段燕麦对干旱胁迫的响应

设中度干旱(MD,土壤田间最大持水量的55±5％)、重度干旱(SD,土壤田间最大持水量的35±5％)两个处理,研究干旱胁迫对温室盆栽燕麦不同生育阶段(苗期、分蘖期、拔节期)的生长性状、叶绿素荧光参数以及根系形态的影响.结果表明,与正常供水(CK)相比,干旱胁迫处理均显著(P<0.05)降低了燕麦苗期、分蘖期、拔节期3个...     

覆盖栽培对烤烟叶绿素、酶活性及丙二醛含量的影响

研究了烤烟大田栽培期间,旺长期揭膜培土后垄上覆盖稻草与旺长期揭膜培土、全生育期覆盖地膜、全生育期覆盖稻草等4种垄体覆盖方式对烤烟叶片叶绿素含量、有关酶活性和丙二醛含量的影响。结果表明：旺长期揭膜培土后垄上覆盖稻草的处理较其他3种处理的叶绿素含量、硝酸还原酶（NR）活性和过氧化物酶（POD）活性略高,而丙二醛（MDA）含量略低;该农艺措施下,上述指标的变化态势与烤烟生长代谢的调控机理基本一致,在信阳乃至黄淮烟区都具有推广利用价值。     

Fruit maturity affects the response of apples to heat stress

Quality changes of apple fruit at different maturity stages in response to heat stress were investigated. ‘Jonagold’ and ‘Cortland’ apples at immature (pre-climacteric), commercial harvest maturity (CHM) and post climacteric maturity (PCM, CHM plus 4 weeks) were harvested and held at 46 °C for 0, 4, 8, or 12 h. Following treatments, fruits were stored in air at 0 °C and evaluated after 0, 1, 2, or 3 months. Quality indices including peel and flesh browning, firmness, titratable acidity, soluble solids, chlorophyll fluorescence (CF), and ethanol production were measured. Results indicated that different cultivars and maturities affected the fruit's resistance to heat stress. ‘Jonagold’ was more resistant to heat stress than ‘Cortland’. Fruit at PCM were most sensitive to heat stress, followed by fruits at CHM and immature stages. When ‘Jonagold’ apples at immature and CHM stages were held at 46 °C for 12 h and then stored for 3 months, flesh browning ratings were negligible compared with 1.4 or 2.9, respectively in ‘Cortland’. Flesh browning rating increased to 1.4 or 4.5 in PCM ‘Jonagold’ held at 46 °C for 8 or 12 h and then stored for 3 months while it was 4.9 or 5.0, respectively, in ‘Cortland’. Heat treatment-induced flesh injury was associated with a decrease in CF. After fruit were exposure to 46 °C for 12 h and then stored for 3 months, Fv/Fm was reduced by 13%, 30%, and 55% in ‘Jonagold’ at immature maturity, CHM and PCM, respectively, while it was reduced by 51%, 58% and 75%, respectively, in ‘Cortland’. Heat stress also caused a decrease in fruit titratable acidity, but had no effect on soluble solids contents. The 8 or 12 h heat treatment resulted in an increase in ethanol production, which was greatest in PCM apples.     

不同砧木对藤稔葡萄光合特性的影响

以少毛变叶葡萄191(LDP-191)、LN33、巨峰为砧木,藤稔为接穗,利用CI-310便携式光合测定仪对在自然条件下藤稔葡萄3种嫁接苗和自根苗的净光合速率、蒸腾速率、气孔导度、光合有效辐射和胞间CO2浓度进行了测定。结果表明:3种嫁接苗与自根苗在晴天的净光合速率的日变化均呈双峰曲线,且3种嫁接组合的净光合速率明显比自根苗的净光合速率高;藤稔自根苗的日均气孔导度明显高于藤稔/LDP-191、藤稔/LN33;不同砧木嫁接的藤稔葡萄光合特性有明显差异,而LDP-191砧木与自根苗相比除净光合速率外其他光合指标均有显著性差异,说明LDP-191砧木对藤稔葡萄是较好的砧木。     

遮荫对茄子幼苗叶片叶绿素荧光特性的影响

研究了不同遮荫处理对茄子幼苗叶绿素荧光参数的影响。结果表明,与全光照条件下相比,遮荫处理使非光化学猝灭系数(NPQ)和光系统激发能压力(1-qP)降低;最大荧光(Fm)、PSII最大光化学效率(Fv/Fm)、PSII潜在活性(Fv/Fo)、PSII实际光化学效率(ФPSII)、天线转化效率(Fv’/Fm’)、光化学荧光猝灭系数(qP)和电子传递速率(ETR)增加。光化学反应的能量(P)在叶片所吸收的光能中所占的比例也逐渐增加,天线色素耗散的能量(D)表现出和P相反的趋势,非光化学反应耗散的能量(E)变化不稳定。以上结果表明,茄子对弱光胁迫有一定的自我调节能力和适应能力,一层遮阳网处理下,茄子幼苗光系统II光化学效率最高,可在育苗生产中应用。     

杂交鳢和乌鳢池塘养殖对比试验

对杂交鳢和乌鳢进行池塘养殖对比试验.前者投喂人工饲料,后者投喂冰鲜鱼,结合水质调控和病害防治等技术,杂交鳢成活率80.9%,乌鳢53.9%;杂交鳢平均单产为5.2 kg/m~2,饵料系数1.367;乌鳢1.8 kg/m~2,饵料系数4.29.整个养殖过程杂交鳢塘换水2次,乌鳢塘换水6次.     

叶面Fe肥对平欧杂种榛树营养元素含量的影响

为初步确定榛园榛树叶片黄化是否由缺Fe或缺Cu引起,对9个不同品种(系)、叶片黄化程度一致的平欧杂种榛树进行了叶面增施Fe肥处理,测定了处理前后榛树叶片内叶绿素和N、P、K、Ca、Mg、Fe、Cu、Mn、Zn的含量,并对两次测定结果进行了比较分析。结果表明,增施Fe肥能有效地使榛树黄化叶片转绿;单独增施Fe肥效果优于合施Fe、Cu肥;增施Fe肥在一定程度上降低了黄化榛树叶片内K、Zn的含量。     

Study of the Protective Effects in PEPC Transgenic Rice

The diurnal course of chlorophyll fluorescence parameter and active oxygen metabolism of flag leaves in PEPC transgenic and untransformed rice Kitaake were studied. The results showed that the photosynthetic rate under high light intensity has been increased by 50% and photoinhibition of photosynthesis in PEPC transgenic was alleviated after the introduction of PEPC gene from maize into rice. It was demonstrated that the increment of photosynthesis in PEPC transgenic was related to the introduction of PEPC gene using specific inhibitor of PEPC. Photoinhibition of photosynthesis in different genotypes exists at noon under natural condition. PEPC transgenic rice exhibited a less decrease in Fv/Fm, a less photoinhibition and a higher efficiency of light energy conversion to chemical energy and lower thermal energy dissipation.These results provided the physiological basis on the mechanism of tolerance to photoinhibition and rice breeding with high photosynthetic efficiency.