Construction of siRNA-survivin and GRIM-19 coexpression plasmid and its growth inhibitory effect on prostatic cancer DU145 cells

AIM: To construct the recombinant plasmid that expresses siRNA-survivin and GRIM-19 simultaneously, and to identify the validity of the recombinant plasmid and observe its effect on expression of survivin and GRIM-19 and proliferation ability of prostate cancer DU145 cells. METHODS: The recombinant plasmid coexpressing siRNA-survivin and GRIM-19 was constructed using gene cloning technique. The prostatic cancer DU145 cells were transfected with the coexpression plasmid and control plasmids. Survivin and GRIM-19 mRNA expression was detected by semi-quantitative RT-PCR. The proliferation ability affected by coexpression plasmid was measured by MTT assay. RESULTS: The coexpression plasmid pGRIM-19-si-survivin was successfully constructed according to DNA recombinant technique and identified through restriction enzyme digestion and plasmid sequencing. Compared with the mock, survivin mRNA expression levels were 0.55?0.05,0.62?0.08 and 0.35?0.05 in psi-survivin, pGRIM-19 and pGRIM-19-si-survivin groups, respectively. Compared with psi-survivin and pGRIM-19, pGRIM-19-si-survivin inhibited survivin mRNA expression markedly (P<0.05), while the expression levels of GRIM-19 mRNA were 1.93?0.14, 2.57?0.20 and 4.12?0.21 in psi-survivin, pGRIM-19 and pGRIM-19-si-survivin groups, respectively (P<0.01). Compared with pGRIM-19 group, pGRIM-19-si-survivin enhanced GRIM-19 mRNA expression more obviously (P<0.05). After transfection for 48 h, the proliferation rates were 58.0%?7.2%, 62.1%?6.1% and 50.2%?4.8% in the 3 experiment groups compared with the mock (P<0.05). After transfection for 72 h, the proliferation rate were 43.4%?4.3%, 51.3%?6.7% and 26.8%?7.1% in experiment groups compared with the mock (P<0.05). Compared with psi-survivin and pGRIM-19, pGRIM-19-si-survivin significantly inhibited the cell growth (P<0.05). CONCLUSION: Transfection of coexpression plasmid pGRIM-19-si-survivin dramatically changes the mRNA expression of survivin and GRIM-19 and inhibits the cell growth.     

Circadian protein Cry2 is a prognostic factor of colorectal cancer and a predictor of chemotherapy

AIM:To assess the association between the expression of Cry2 and the prognosis of colorectal cancer for determining the role of Cry2 in predicting the outcome of chemotherapy. METHODS:Sixteen primary colorectal cancer patients who consecutively underwent neoadjuvant chemotherapy with 5-fluorouracil were enrolled in the present study. The tumor specimens were obtained by colonscopy prior to treatment. The tumor response was evaluated by the response evaluation criteria in solid tumors(RECIST). Accordingly, the patients were divided into 2 groups:complete response(CR)/partial response(PR) and stable disease(SD)/progress disease(PD). Two-tail ² test was applied to analyze the data. In parallel, we assessed 307 patients, who underwent tumor resection between 2001 and 2005. Survival time was calculated from the date of surgery to the date of death or the last follow-up date. Survival curves were obtained by Kaplan-Meier method. Log-rank test was applied for univariate analysis. The Cox proportional hazards regression model was used to identify the independent prognostic factors. RESULTS:The expression of Cry2 was high in CR/PR patients and was low in SD/PD patients, with significant difference(P<0.05). The average survival time of the 84 patients with high expression of Cry2 was 83.458 months, while the average survival time of 223 patients with low expression of Cry2 was 100.10 months, also with significant difference(P<0.05). The patients with low expression of Cry2 lived longer. The multivariate Cox regression analysis indicated that the expression of Cry2 was an independent prognostic factor for colorectal cancer patients(HR was 1.70, 95% CI was 1.09 to 2.66, P<0.05). Multivariate Cox regression showed that high Cry2 expression predicted a worse prognosis(HR was 2.88, 95%CI was 1.03 to 8.06, P<0.05) in colorectal cancer patients with neoadjuvant chemotherapy. CONCLUSION:Expression of Cry2 is an independent prognostic factor for colorectal cancer patients. Lower expression of Cry2 indicates good response to neoadjuvant chemotherapy.     

多效唑对无患子的矮化效应

采用不同浓度的多效唑对无患子进行矮化试验,结果表明:适宜浓度的多效唑可使无患子高生长减缓、茎杆加粗、叶面积降低、叶绿素含量增高,以多效唑1g·L-1处理对无患子的矮化作用效果最好.     

猪细小病毒PCR检测与分离研究

根据猪细小病毒(PPV)结构蛋白VP2基因序列,设计合成1对引物,建立了检测PPV的PCR方法。检测14份临床组织,检出阳性11份,阳性检出率为79.5%。阳性样品扩增产物用EcoRⅠ酶切得到了预期的结果,对PCR产物进行测序,测序结果与已发表的PPV基因核苷酸序列比较,同源性达99%~100%,所编码的氨基酸同源性为93%~100%。从PCR检测阳性的一份病料组织中分离出1株PPV。试验证明,建立的PPVPCR检测方法特异性强、敏感性高,适用于临床样品的快速检测。     

不同生态区8种芸芥根系生物量的初步研究

通过管栽模拟试验,研究了不同生态区8个芸芥类型(高抗旱类型的会宁芸芥、陇西芸芥,中抗旱类型的张北芸芥、Varomin芸芥、兴和芸芥、和田芸芥,低抗旱类型的西凉芸芥、四川芸芥)的根系生长情况。结果表明:芸芥根系生物量的垂直层次分布模型可用多项式y=a bx cx2 dx3描述;会宁、陇西、兴和、西凉芸芥与张北、和田、Varomin、四川芸芥的各参数值(a、b、c、d)总体相差较大且根系总生物量、各层次的生物量和根/冠比前者均低于后者;各层次根系生物量的百分含量也呈现不同的垂直变化规律。无论是总的还是各层次的根系生物量,强抗旱芸芥类型的趋于中等大小,中抗芸芥类型的有大也有小,低抗芸芥类型的均较大。     

回交自交系(BIL)群体4对主基因加多基因混合遗传模型分离分析方法的建立

主基因加多基因混合遗传模型是用于分析数量性状表型数据的统计分析方法, 该方法便于育种工作者利用杂种分离世代的数据对育种性状的遗传组成初步判断,制定相应的育种策略,也可用于校验QTL定位所揭示的数量性状的性状遗传组成。回交自交系(BIL)群体是永久性群体,可以进行有重复的比较试验,适用于受环境影响较大的复杂性状的遗传研究。本研究以BIL群体为对象构建了４对主基因、主基因加多基因分离分析方法的遗传模型,包括2类11个遗传模型。利用基于IECM (iterative expectation conditional maximization)算法的极大似然分析方法估算各个混合遗传模型中的分布参数,用AIC值和一组适合性测验结果选取最优模型,并从入选模型的分布参数通过最小二乘法估计遗传参数。由1个模拟的随机区组试验对模型进行验证,模拟群体中遗传参数的估计值与设定值之间具有很好的一致性。利用本文建立的模型重新分析大豆回交自交系群体(Essex×ZDD2315)及其亲本对胞囊线虫(Heterodera glycines Ichinohe) 1号生理小种的抗性数据后发现4对主基因模型优于原报道的3对主基因模型,说明本方法的有效性和正确性。     

高光谱遥感估测大豆冠层生长和籽粒产量的探讨

现代作物育种需要监测大量育种材料的生长并估测产量潜势, 高光谱遥感技术为此提供了简单、快捷、非损伤性测定的可能途径。选取30份大豆育成品种进行连续2年的产量比较试验, 在盛花期(R2)、盛荚期(R4)和鼓粒始期(R5)测定地上部生物量(ADM)和叶面积指数(LAI), 并利用ASD高光谱地物仪同步收集大豆冠层反射光谱信息。供试品种间ADM、LAI和产量差异显著或极显著。不同生育期可见光和近红外区域的光谱反射率与大豆ADM、LAI及产量均有显著相关, 尤其在R4和R5期相关性最高。在构建大量光谱参数的基础上, 遴选出对ADM、LAI及产量预测精度较好的回归模型。其中, R5期的P_Area560光谱参数与LAI和R4期的V_Area1450光谱参数与ADM构建的两个生长性状的监测模型效果最好, 决定系数(R²)分别为0.582和0.692。未发现单一生育期光谱参数对大豆估产的有效模型, 但综合R2期NPH1280、R4期V_Area1190以及R5期NPH560构建的产量估测模型, 决定系数(R²)达到0.68, 效果较好。本研究     

利用棉花纤维品质相关QTL评价海陆渐渗品种品质初探

 选用第7、13、25号染色体上纤维品质相关QTL(Quantitative trait locus)密集分布区间的48对SSR（Simple sequence repeat）引物,对48份棉花种质进行多态性检测,研究结果显示在实验材料中3对SSR引物具有陆海差异多态性,相关分析表明3个优质基因SSR位点与纤维长度和纤维强度达到极显著相关。通过与海岛棉带型比对、追踪,从分子水平上明确了这些品种中来源于海岛棉渐渗于陆地棉的优异基因区段,为下一步分子标记辅助聚合育种提供了理论参考。     

温度与土壤水分对玉米种子萌发及幼苗生长特性的影响

以沈单16、豫玉22为试验材料,研究不同温度、土壤水分对玉米种子萌发及幼苗生长特性的影响.结果表明,随温度与土壤水分的下降种子发芽势、发芽率均呈降低趋势.温度与土壤水分对幼苗生长各指标的影响不同,玉米芽鞘长、幼苗长、贮藏物质转运率和叶绿素含量均随温度与土壤含水量的降低而减小;过氧化物酶活性、脯氨酸含量呈先增加后降低的趋势.在环境温度低于15℃恒温条件下,玉米种子发芽率迅速降低,土壤含水量低于10％时种子不能正常萌发;在15℃及以下低温,土壤含水量低于10％时玉米幼苗生长受到抑制.持续性低温、干旱胁迫不利于玉米种子的正常萌发与幼苗的生长.     

秸秆还田与覆膜对土壤理化特性及玉米生长发育的影响

试验研究秸秆还田对不同覆膜时期的全膜双垄沟播玉米生长发育与土壤理化特性的影响。结果表明,经秸秆还田后全膜双垄沟播耕层土壤养分含量变化依次表现为整株还田>秸秆粉碎>免耕留茬,不同覆膜时间对土壤养分变化影响不明显;秸秆还田土壤容重明显降低但免耕留茬一膜两年用处理土壤容重增大。在玉米生育前期经秸秆还田后的土壤温度与水分均显著低于对照,其株高、茎粗与叶面积均小于对照;在玉米生育后期秸秆腐解后对土壤水分起到一个补偿效应。玉米产量表现为秋覆膜整株秸秆还田>顶凌覆膜整株秸秆还田>秋覆膜秸秆粉碎还田>顶凌覆膜秸秆粉碎还田>免耕留茬一膜两年用,秸秆还田后玉米产量较对照有增产趋势,而免耕留茬一膜两年用有减产倾向,但处理间差异不显著。