cDNA芯片技术杂交效率的优化

目的 cDNA芯片杂交影响因素很多 ,如固定于玻片的DNA片段的浓度、溶解DNA片段的点样液、荧光探针浓度及纯度杂交液、杂交温度、杂交时间和Cy3与Cy5荧光素标记探针等 ,本实验针对其中重要影响因素进行优化筛选 ,以提高杂交效率。方法 通过逐一改变cDNA杂交技术重要影响因素的实验条件 ,平行设置多组实验 ,从中筛选出最佳实验数据。结果与结论 重复实验结果表明 ,杂交效率较高的条件为 :浓度约为 0 5 0 μg·μL- 1 DNA片段 ,溶于 1×MicroSpottingSolution(ArrayItTM)中 ,与纯化后的荧光标记在 0 5 %SDS 10×SSC甲酰胺杂交液 ,在 4

在载玻片上制备高杂交效率的DNA芯片

目的 :改进玻璃基质上固定DNA的方法 ,提高固定DNA的杂交效率 .方法 :玻片用 β -(对、间氯甲基苯基 )三氯硅乙烷和 β -苯基三氯硅乙烷二组分混合硅烷化试剂处理 ,再用NaI丙酮溶液处理 ,在表面自组装形成带有苄碘功能基的二组分混合单层硅烷膜 .巯基修饰的DNA共价偶联到这一自组装的硅烷膜上 .结果 :放射性分析证实玻璃基质表面共价固定DNA的优化密度为9 3× 10 - 2 μmol/m2 ,目标DNA杂交密度为 8.6× 10 - 2 μmol/m2 ,固定DNA的杂交率为 93% .结论 :采用两步竞争性反应的方法能够较容易地控制DNA在芯片上的固定密度 ,固定的DNA在芯片分布较均匀 ,因此制得的DNA芯片具有较高杂交效率和杂交密度 。

有效提高大豆有性杂交效率的途径研究

通过对杂交过程中多环节有效控制,杂交效率有了大幅度提升,突出表现在:每人每天完成4～6个组合(每个组合40朵花),每人每小时完成80～100朵花;成活率一般在60%～70%,高者可达80%以上。

辣椒杂交种子生产的杂交效率

杂交种子生产是杂交辣椒育种中最耗费劳动的工作部分。利用雄性不育系，虽可取消去雄，可以减少很多工作量，但其授粉过程仍必不可少。Messhram和Mukewar(1985)以及Gill(1995)试验表明，利用昆虫授粉效果不佳，而人工授粉效果很好。利用可育系生产杂交种子，很多因素，如去雄和授粉方法、植株生长状况及材料的生理和遗传特征等都决定F1代种子生产的效率。

Photosynthetic Characteristics of Two Superhigh-yield Hybrid Rice

The photosynthetic functions and the sensitivity to photoinhibition were compared between two superhigh_yield hybrid rice (Oryza sativa L.) Liangyoupeijiu and X07S/Zihui 100, the newly developed from two parental lines and traditional hybrid rice Shanyou 63 developed from three parental lines. The results showed that, as compared to Shanyou 63, the net photosynthetic rate of Liangyoupeijiu and X07S/Zihui 100 was 9.1% and 11.9% higher, the transpiration rate was 37.4% and 31.4% lower, and their water use efficiency was 74.2% and 63.5% higher respectively. After strong light (2 000 μmol photons·m -2 ·s -1 ) treatment for 2 h, the photochemical quantum yield and the photochemical quenching increased by 37.0% and 18.0% respectively in Liangyoupeijiu, 28.3% and 46.2% in X07S/Zihui 100, but decreased a little in Shanyou 63. The non_photochemical quenching decreased in Liangyoupeijiu and X07S/Zihui 100 (about 50%) but increased greatly in Shanyou 63 (about 50%). Better photosynthetic functions, higher water use efficiency and stronger resistance to photoinhibition, may be the physiological basis for the super high_yield of the two hybrid rice under study.

胚胎植入前诊断中多轮荧光原位杂交效果及影响因素分析

目的探讨胚胎植入前诊断（preimplantation genetic diagnosis，PGD）中多轮荧光原位杂交（fluorescense in situ hybridization，FISH）效果及其影响因素。方法48对夫妇因染色体异常（罗伯逊易位24对、相互易位16对、臂间倒位2对）或其他原因（女方高龄且生育过唐氏综合征患儿1对、男方或女方性染色体异常3对、反复自然流产史2对）行PGD，经72个采卵周期获得≥6细胞胚胎432个，受精后第3天行胚胎活检，对396枚完整核进行FISH，对信号不明确的核进行下一轮杂交，396枚核共进行了1～6轮870次杂交，分析比较各轮杂交信号明确率、不同探针对杂交效果的影响以及导致信号不明确的相关因素。结果870次杂交中535次信号明确，占比61．5％，第2轮和第3轮信号明确率分别为71．8％和77．4％，显著高于第1轮（52．8％，P〈0．01）、第4轮（55．8％，P〈0．05、P〈0．01）、第5轮（54．5％，P（O．05）和第6轮（27．3oA，P〈0．01）。着丝粒探针组（centromere specific probe，CEP）总体信号明确率80．3％，该组前3轮信号明确率最高，分别为85．7％、85．1％和88．0％，3轮间差异无统计学意义，第4轮起信号明确率明显下降，第4、第5轮与前3轮比有显著差异；其他探针组总体信号明确率55．2％（与CEP探针组比较，P〈0．01），该组第5轮信号明确率最高（72．7％），第2轮信号明确率（66．1％）显著高于第1轮和第6轮（P〈0．01），第3轮信号明确率（63．8％）与其他各轮相比差异无统计学意义。6轮FISH中335次信号不明确，原因依次为信号质量差（20．9％，182／870）、背景干扰（7．6％，66／870）、杂交失败（6．1％，53／870）、核破损（1．8％，16／870）、核丢失（1．1％，10／870）、信号分裂／重叠（0．9％，8／870）。结论多轮FISH能提高PGD中单个核的利用价值，以前3轮效果最好；CEP杂交效果优于其他探针；信号质量差是导致信号不明确的最常见原因。

猪腹泻病毒可视化基因芯片的两种靶基因标记技术的比较

本研究同时采用常规PCR和不对称PCR分别进行靶基因片段生物素标记,应用于金标银染可视化基因芯片,分析其对猪腹泻病毒可视化共检基因芯片杂交效率的影响。分别选取猪流行性腹泻病毒（porcine epidemic diarrhea virus,PEDV）的S和M基因,猪传染性胃肠炎病毒（transmissible gastroenteritis virus of swine,TGEV）的N和S基因,A型猪轮状病毒（group A porcine rotavirus,GAR）的VP7和NSP4基因设计引物。根据目的基因片段设计60-mer寡核苷酸探针,在其5′端修饰15个T碱基后,利用芯片点样仪喷样于醛基玻片上制成基因芯片。应用常规PCR和不对称PCR两种生物素标记方法,对本实验室构建保存的三种腹泻病毒的阳性质粒进行生物素掺入标记,在相同条件下与基因芯片进行杂交。利用生物素-链霉亲和素的特异性链接,将链霉亲和素修饰的纳米金颗粒引入反应体系,通过银离子染色后直接眼观试验结果。结果表明,应用此可视化共检芯片特异性好,CSFV、PRRSV、PCV2、JEV杂交结果均呈阴性。不对称PCR标记法可有效提高杂交效率,不对称PCR标记技术和常规PCR标记技术的最低检测浓度分别为10^5copies/L和10^7copies/L,前者的灵敏性是后者的10～100倍。应用不对称PCR标记技术对样品进行生物素标记后,可明显提高腹泻病毒可视化共检芯片的杂交效率,有利于检测型可视化基因芯片的应用。

Evaluation of the yield and nitrogen use efficiency of the dominant maize hybrids grown in North and Northeast China

Breeding high-yielding and nutrient-efficient cultivars is one strategy to simultaneously resolve the problems of food security,resource shortage,and environmental pollution.However,the potential increased yield and reduction in fertilizer input achievable by using high-yielding and nutrient-efficient cultivars is unclear.In the present study,we evaluated the yield and nitrogen use efficiency(NUE) of 40 commercial maize hybrids at five locations in North and Northeast China in 2008 and 2009.The effect of interaction between genotype and nitrogen(N) input on maize yield was significant when the yield reduction under low-N treatment was 25%-60%.Based on the average yields achieved with high or low N application,the tested cultivars were classified into four types based on their NUE:efficient-efficient(EE) were efficient under both low and high N inputs,high-N efficient(HNE) under only high N input,low-N efficient(LNE) under only low N input,and nonefficient-nonefficient under neither low nor high N inputs.Under high N application,EE and HNE cultivars could potentially increase maize yield by 8%-10% and reduce N input by 16%-21%.Under low N application,LNE cultivars could potentially increase maize yield by 12%.We concluded that breeding for N-efficient cultivars is a feasible strategy to increase maize yield and/or reduce N input.

A novel improved SLM scheme of the PAPR reduction technology in CO-OFDM systems

The higher peak-to-average power ratio(PAPR) is a major shortcoming of coherent optical orthogonal frequency division multiplexing(CO-OFDM) systems. Selective mapping(SLM) technology can effectively reduce the probability of high PAPR, but it has higher computational complexity, and requires additional bandwidth to transmit the side information, which will affect the transmission efficiency of the system. In response to these shortcomings, a novel improved SLM(NI-SLM) scheme with low complexity and without side information is proposed. Simulation results show that the proposed scheme can exponentially reduce the computational complexity, and the bit error rate(BER) performance can greatly approach the original signal. What's more, it shows the better PAPR reduction performance.