The next generation sequencing enables generation of high resolution and high throughput data for structure sequence of any genome at a fast declining cost. This opens opportunity for population based genetic and geno...The next generation sequencing enables generation of high resolution and high throughput data for structure sequence of any genome at a fast declining cost. This opens opportunity for population based genetic and genomic analyses. In many applications, whole genome sequencing or re-sequencing is unnecessary or prohibited by budget limits. The Reduced Representation Genome Sequencing （RRGS）, which sequences only a small proportion of the genome of interest, has been proposed to deal with the situations. Several forms of RRGS are proposed and implemented in the literature. When applied to plant or crop species, the current RRGS protocols shared a key drawback that a significantly high proportion （up to 60%） of sequence reads to be generated may be of non-genomic origin but attributed to chloroplast DNA or rRNA genes, leaving an exceptional low efficiency of the sequencing experiment. We recommended and discussed here the design of optimized simplified genomic DNA and bisulfite sequencing strategies, which may greatly improves efficiency of the sequencing experiments by bringing down the presentation of the undesirable sequencing reads to less than 10% in the whole sequence reads. The optimized RAD- seq and RRBS-seq methods are potentially useful for sequence variant screening and genotyping in large plant/crop populations.展开更多
目的:检测Ras相关区域家族1A(Ras association domain family 1A,RASSF1A)在胰腺癌细胞株中的甲基化和表达状态,探讨其启动子异常甲基化在胰腺癌发病过程中的作用。方法:采用重亚硫酸盐测序PCR(bisulfite genomic sequencing PCR,BSP)联...目的:检测Ras相关区域家族1A(Ras association domain family 1A,RASSF1A)在胰腺癌细胞株中的甲基化和表达状态,探讨其启动子异常甲基化在胰腺癌发病过程中的作用。方法:采用重亚硫酸盐测序PCR(bisulfite genomic sequencing PCR,BSP)联合TA克隆测序检测胰腺癌细胞株PANC-1及胰腺癌组织、癌旁组织及正常胰腺组织中RASSF1A启动子区CpG岛的甲基化状态,以甲基化酶抑制剂5-aza-2-deoxycitydine(5-aza-dC)处理PANC-1,观察处理前后甲基化率变化情况,逆转录PCR观察RASSF1A的mRNA表达情况。结果:在PANC-1细胞中RASSF1A启动子的甲基化率平均为100.00%,在正常胰腺、癌旁及癌组织中平均分别为1.79%、93.75%和100.00%,与正常胰腺组织相比,胰腺癌旁及癌组织的RASSF1A启动子甲基化率明显增高(P<0.01),而癌旁及癌组织之间无明显差异(P>0.05)。在PANC-1细胞、胰腺癌组织及癌旁组织中RASSF1A基因无表达,在正常胰腺组织中RASSF1A基因呈阳性表达;PANC-1细胞经5-aza-dC处理后,RASSF1A的甲基化率下降(88.89%,P<0.05),mRNA表达无变化。结论:胰腺癌细胞株PANC-1及癌组织、癌旁组织RASSF1A基因表达与启动子区甲基化状态有关,启动子区的高甲基化导致PANC-1中RASSF1A基因的表达沉默。该基因异常甲基化有望成为胰腺癌的早期诊断指标和治疗靶点。展开更多
基于限制位点相关的DNA(restriction site associated DNA,RAD)标记的测序方法是一种新型的测序技术.其优点是不仅节省传统测序的试验成本,而且能快速准确的定位出数以千计的基因标记,从而更加适合分子辅助育种的应用.该方法可应用于寻...基于限制位点相关的DNA(restriction site associated DNA,RAD)标记的测序方法是一种新型的测序技术.其优点是不仅节省传统测序的试验成本,而且能快速准确的定位出数以千计的基因标记,从而更加适合分子辅助育种的应用.该方法可应用于寻找DNA多态性,鉴别SNP,构建未知基因组序列生物的遗传图谱,定位目的性状基因等.本文主要综述了RAD标记和RAD测序的研究进展及其在分子育种中的应用.展开更多
文摘目的:建立线粒体DNA(mitochondrial DNA,mtDNA)缺失肝癌SK-Hep1细胞(ρ°SK-Hep1)的转线粒体模型(cybrid,Cyb),探讨mtDNA缺失诱导人肝癌细胞多药耐药表型产生的可能机制。方法:采用聚乙二醇融合法,将正常人血小板融合入ρ°SK-Hep1细胞,建立ρ°SK-Hep1细胞转线粒体模型SK-Hep1Cyb,并采用PCR、Southern杂交进行鉴定;计数法描绘细胞生长曲线,计算倍增时间;Transwell实验检测细胞侵袭能力,MTT法检测药物敏感性,Western印迹法检测细胞中P-糖蛋白(P-glycoprotein,P-gp)、多药耐药相关蛋白1(multidrug resistance-associated protein 1,MRP1)和Bcl-2的表达水平。结果:PCR、Southern杂交证实ρ°SK-Hep1融合了正常人血小板线粒体,成功建立了转线粒体细胞模型SK-Hep1Cyb。ρ°SK-Hep1细胞群体倍增时间明显缩短(P<0.01),生长速度加快,侵袭能力增强;与SK-Hep1细胞和SK-Hep1Cyb细胞相比,ρ°SK-Hep1细胞对化疗药物耐药性增强,细胞内P-gp、MRP1和Bcl-2蛋白表达增加。结论:采用细胞融合技术成功建立了ρ°SK-Hep1细胞的转线粒体模型。P-gp、MRP1和Bcl-2蛋白表达增加在mtDNA缺失诱导多药耐药表型产生中可能具有一定的作用。
文摘The next generation sequencing enables generation of high resolution and high throughput data for structure sequence of any genome at a fast declining cost. This opens opportunity for population based genetic and genomic analyses. In many applications, whole genome sequencing or re-sequencing is unnecessary or prohibited by budget limits. The Reduced Representation Genome Sequencing （RRGS）, which sequences only a small proportion of the genome of interest, has been proposed to deal with the situations. Several forms of RRGS are proposed and implemented in the literature. When applied to plant or crop species, the current RRGS protocols shared a key drawback that a significantly high proportion （up to 60%） of sequence reads to be generated may be of non-genomic origin but attributed to chloroplast DNA or rRNA genes, leaving an exceptional low efficiency of the sequencing experiment. We recommended and discussed here the design of optimized simplified genomic DNA and bisulfite sequencing strategies, which may greatly improves efficiency of the sequencing experiments by bringing down the presentation of the undesirable sequencing reads to less than 10% in the whole sequence reads. The optimized RAD- seq and RRBS-seq methods are potentially useful for sequence variant screening and genotyping in large plant/crop populations.
文摘目的:检测Ras相关区域家族1A(Ras association domain family 1A,RASSF1A)在胰腺癌细胞株中的甲基化和表达状态,探讨其启动子异常甲基化在胰腺癌发病过程中的作用。方法:采用重亚硫酸盐测序PCR(bisulfite genomic sequencing PCR,BSP)联合TA克隆测序检测胰腺癌细胞株PANC-1及胰腺癌组织、癌旁组织及正常胰腺组织中RASSF1A启动子区CpG岛的甲基化状态,以甲基化酶抑制剂5-aza-2-deoxycitydine(5-aza-dC)处理PANC-1,观察处理前后甲基化率变化情况,逆转录PCR观察RASSF1A的mRNA表达情况。结果:在PANC-1细胞中RASSF1A启动子的甲基化率平均为100.00%,在正常胰腺、癌旁及癌组织中平均分别为1.79%、93.75%和100.00%,与正常胰腺组织相比,胰腺癌旁及癌组织的RASSF1A启动子甲基化率明显增高(P<0.01),而癌旁及癌组织之间无明显差异(P>0.05)。在PANC-1细胞、胰腺癌组织及癌旁组织中RASSF1A基因无表达,在正常胰腺组织中RASSF1A基因呈阳性表达;PANC-1细胞经5-aza-dC处理后,RASSF1A的甲基化率下降(88.89%,P<0.05),mRNA表达无变化。结论:胰腺癌细胞株PANC-1及癌组织、癌旁组织RASSF1A基因表达与启动子区甲基化状态有关,启动子区的高甲基化导致PANC-1中RASSF1A基因的表达沉默。该基因异常甲基化有望成为胰腺癌的早期诊断指标和治疗靶点。
文摘基于限制位点相关的DNA(restriction site associated DNA,RAD)标记的测序方法是一种新型的测序技术.其优点是不仅节省传统测序的试验成本,而且能快速准确的定位出数以千计的基因标记,从而更加适合分子辅助育种的应用.该方法可应用于寻找DNA多态性,鉴别SNP,构建未知基因组序列生物的遗传图谱,定位目的性状基因等.本文主要综述了RAD标记和RAD测序的研究进展及其在分子育种中的应用.
