为研究凡纳滨对虾适应低温的分子机理,实验对从低温处理凡纳滨对虾抑制性消减文库中筛选出的一个360 bp EST序列进行了研究。首先,同源比对显示该EST片段与其他物种的ANT2基因高度同源,命名为凡纳滨对虾ANT2基因(LVANT2);其次,通过构建...为研究凡纳滨对虾适应低温的分子机理,实验对从低温处理凡纳滨对虾抑制性消减文库中筛选出的一个360 bp EST序列进行了研究。首先,同源比对显示该EST片段与其他物种的ANT2基因高度同源,命名为凡纳滨对虾ANT2基因(LVANT2);其次,通过构建凡纳滨对虾肝胰腺全长cDNA文库,PCR扩增获得LVANT2基因的全长cDNA1540 bp,其中包括1011 bp的完整开放阅读框,编码336个氨基酸残基。然后,对基因进行了不同组织和低温处理的表达谱分析:(1)组织表达谱的结果显示,该基因在凡纳滨对虾肌肉组织中表达量最高;(2)在不同低温处理下的表达结果显示,该基因在15℃处理下基因表达量发生显著变化,13℃开始呈下调表达,11℃时表达量又升高;13℃低温处理不同时间发现该基因在12h内表达量发生显著变化,48h后表达量最高。LVANT2基因的低温诱导表达模式说明其可能在凡纳滨对虾低温适应中发挥作用。展开更多
Objective To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization.Methods Polyadenylated RNA ［Poly (A)+ RNA］ was isolated from tissues of RCC and normal kidne...Objective To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization.Methods Polyadenylated RNA ［Poly (A)+ RNA］ was isolated from tissues of RCC and normal kidney, and single-strand cDNAs and double-strand cDNAs were synthesized in turn. RCC cDNAs were divided into two groups and ligated to the specific adaptors l and 2, and then hybridized with normal kidney cDNA twice with two rounds of suppression PCR. Second round PCR products were cloned to T/A plasmid vectors to set up the subtractive library. One hundred clones were randomly picked to perform enzyme digest analysis, and some underwent sequence analysis and Northern blot to identify RCC specifically expressed genes. SMART RACE procedure was operated to clone full length novel RCC specifically expressed genes.Results A human RCC subtractive library with high subtractive efficiency was successfully set up. The amplified library contains 350 positive clones. Random analysis of 100 clones with enzyme restriction showed that 85 plasmids in the clones contained 50-400?bp inserts. Sequence analysis was performed for 10 clones. All the 10 sequences were unknown before and derived from 6 unique, novel genes among which the cDNA insert RCC18 had five copies. Northern blot analysis showed that RCC18 cDNA was highly expressed in RCC, but no signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of the novel gene RCC18.Conclusions The constructed cDNA subtractive library of human RCC is a highly efficient one and lays a solid foundation for large scale screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel specifically expressed genes provided an important clue for studying the mechanisms of occurrence and development of RCC.展开更多
文摘为研究凡纳滨对虾适应低温的分子机理,实验对从低温处理凡纳滨对虾抑制性消减文库中筛选出的一个360 bp EST序列进行了研究。首先,同源比对显示该EST片段与其他物种的ANT2基因高度同源,命名为凡纳滨对虾ANT2基因(LVANT2);其次,通过构建凡纳滨对虾肝胰腺全长cDNA文库,PCR扩增获得LVANT2基因的全长cDNA1540 bp,其中包括1011 bp的完整开放阅读框,编码336个氨基酸残基。然后,对基因进行了不同组织和低温处理的表达谱分析:(1)组织表达谱的结果显示,该基因在凡纳滨对虾肌肉组织中表达量最高;(2)在不同低温处理下的表达结果显示,该基因在15℃处理下基因表达量发生显著变化,13℃开始呈下调表达,11℃时表达量又升高;13℃低温处理不同时间发现该基因在12h内表达量发生显著变化,48h后表达量最高。LVANT2基因的低温诱导表达模式说明其可能在凡纳滨对虾低温适应中发挥作用。
文摘为解析糙皮侧耳原基期与菌丝期差异表达的基因,本研究以原基期c DNA为检测子(tester)、双核菌丝期c DNA为驱赶子(driver),采用抑制性消减杂交法(suppression subtractive hybridization,SSH)构建了糙皮侧耳SSH c DNA文库。菌液PCR验证SSH c DNA文库插入c DNA片段后,挑取了2 055个差异转化子,差异转化子经3次反向Northern杂交筛选,得423个信号差异显著的克隆;阳性克隆测序后,经NCBI数据库Blastn和Blastx比对,共得206条差异表达序列(expressed sequence tag,EST),重复序列去除后,有46个基因参与了细胞急救和防御、能量代谢、转录和蛋白调控、膜蛋白和信号转导,18个基因编码未知功能的推定蛋白,5个无任何同源性的新基因。挑取10个差异表达基因进行半定量RT-PCR,发现这些序列在原基期的表达水平显著高于菌丝期。结果表明,本研究成功构建了糙皮侧耳原基期与菌丝期SSH c DNA文库,为进一步分离糙皮侧耳生长发育相关基因并研究糙皮侧耳的发育机制奠定了基础。
基金ThisprojectwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No 39870 841)
文摘Objective To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization.Methods Polyadenylated RNA ［Poly (A)+ RNA］ was isolated from tissues of RCC and normal kidney, and single-strand cDNAs and double-strand cDNAs were synthesized in turn. RCC cDNAs were divided into two groups and ligated to the specific adaptors l and 2, and then hybridized with normal kidney cDNA twice with two rounds of suppression PCR. Second round PCR products were cloned to T/A plasmid vectors to set up the subtractive library. One hundred clones were randomly picked to perform enzyme digest analysis, and some underwent sequence analysis and Northern blot to identify RCC specifically expressed genes. SMART RACE procedure was operated to clone full length novel RCC specifically expressed genes.Results A human RCC subtractive library with high subtractive efficiency was successfully set up. The amplified library contains 350 positive clones. Random analysis of 100 clones with enzyme restriction showed that 85 plasmids in the clones contained 50-400?bp inserts. Sequence analysis was performed for 10 clones. All the 10 sequences were unknown before and derived from 6 unique, novel genes among which the cDNA insert RCC18 had five copies. Northern blot analysis showed that RCC18 cDNA was highly expressed in RCC, but no signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of the novel gene RCC18.Conclusions The constructed cDNA subtractive library of human RCC is a highly efficient one and lays a solid foundation for large scale screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel specifically expressed genes provided an important clue for studying the mechanisms of occurrence and development of RCC.
