Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using co...Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using complementary DNA (cDNA) derived from messenger RNA (mRNA) extracted from plant tissues and generated by reverse transcription. However, some CDS are difficult to acquire through this process as they are expressed at extremely low levels or have specific spatial and/or temporal expression patterns in vivo. These challenges require the development of alternative CDS cloning technologies. In this study, we found that the genomic intron-containing gene coding sequences (gDNA) from Arabidopsis thaliana, Oryza sativa, Brassica napus, and Glycine max can be correctly transcribed and spliced into mRNA in Nicotiana benthamiana. In contrast, gDNAs from Triticum aestivum and Sorghum bicolor did not function correctly. In transient expression experiments, the target DNA sequence is driven by a constitutive promoter. Theoretically, a sufficient amount of mRNA can be extracted from the N. benthamiana leaves, making it conducive to the cloning of CDS target genes. Our data demonstrate that N. benthamiana can be used as an effective host for the cloning CDS of plant genes.展开更多
Using normal brain cell geneomic DNA as a template,transforming growth factor(TGFa)-IV exon gene was amplified by polymerase chain reaction(PCR). The sequence of amplified fragment was analysed with a DNA sequencing k...Using normal brain cell geneomic DNA as a template,transforming growth factor(TGFa)-IV exon gene was amplified by polymerase chain reaction(PCR). The sequence of amplified fragment was analysed with a DNA sequencing kit.The results showed that the cloned fragment is proved to be the TGFa-IV exon gene.展开更多
AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of C...AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of China, these factors are not so important in the etiology of HCC. Therefore, the point mutation of p53 exon7 may also be different than that in HCC-prevalent areas of China. The aim of this study is to investigate the status and carcinogenic role of the point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province, a non-HCC-prevalent area in China. METHODS: PCR PCR-SSCP and PCR-RFLP were applied to analyze the homozygous deletion and point mutation of p53 exon7 in HCC samples from Anhui, which were confirmed by DNA sequencing and Genbank comparison. RESULTS: In the 38 samples of hepatocellular carcinoma, no homozygous deletion of p53 exon7 was detected and point mutations of p53 exon7 were found in 4 cases, which were found to be heterozygous mutation of codon 249 with a mutation rate of 10.53%(4/38). The third base mutation(G-T) of p53 codon 249 was found by DNA sequencing and Genbank comparison. CONCLUSION: The incidence of point mutation of p53 codon 249 is lower in hepatocellular carcinoma and the heterozygous mutation of p53 exon7 found in these patients only indicate that they have genetic susceptibility to HCC. p53 codon 249 is a hotspot of p53 exon7 point mutation, suggesting that the point mutation of p53 exon 7 may not play a major role in the carcinogenesis of HCC in Anhui Province, a non-HCC-prevalent area in China.展开更多
Summary: To examine the deletion and point mutation of WWOX (WW domain containing oxidoreductase) exons 6-8 in human non-small cell lung cancer and their possible relationship with pathological stages, tumor tissues ...Summary: To examine the deletion and point mutation of WWOX (WW domain containing oxidoreductase) exons 6-8 in human non-small cell lung cancer and their possible relationship with pathological stages, tumor tissues and the corresponding normal tissues were obtained from 44 Chinese patients who had undergone surgery for non-small cell lung cancer. RNA was extracted from each sample and deletion and mutation of WWOX exons 6-8 were analyzed by RT-PCR and DNA sequencing. Our results showed that 28 of 44 (63.6 %) lung cancer samples showed loss of WWOX exons 6-8 transcript and the deletion was detected in only 3 of 44 (6.8 %) corresponding adjacent normal tissues (P<0.05). The transcript sequencing analyses of the 16 lung cancer samples without transcript loss of WWOX exons 6-8 revealed no difference from the sequence of GenBank. Moreover, the deletion of WWOX exons 6-8 was significantly higher in the smokers when compared with the non-smokers. It is also higher in the men and squamous carcinomas than in women and adenocarcinomas (P<0.05). The deletion, however, was not found to be associated with pathological stages of the tumors. Our study documented a high incidence of deletion of WWOX exons 6-8 in non-small cell lung cancer in Chinese patients and suggested that the frequent loss of WWOX exons 6-8 might play an important role in the tumorigenesis of non-small cell lung cancer in Chinese. WWOX exons 6-8 may serves as a candidate molecular target of smoking carcinogenesis, and point mutation is not a predominant way of alteration of WWOX exons 6-8.展开更多
The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;it...The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;its entire –CH3 served instead for building N6-methyladenine and 5-methylcytosine on bacterial DNA and 5-methylcytosine alone on human DNA. In humans, although a slight extra-S asymmetric methylation appeared de novo yielding on parental DNA 5’-m5CpC-3’/ 3’-GpG-5’, 5’-m5CpT-3’/3’-GpA-5’ and 5’-m5CpA-3’/3’-GpT-5’ monomethylated dinucleotide pairs, a heavy symmetric methylation involved in S semiconservatively newly made DNA to guarantee genetic maintenance of –CH3 in 5’-m5CpG-3’/3’-Gpm5C-5’ dimethylated dinucleotide pairs. In this framework, an inverse correlation was found between bulk genomic DNA methylation occurring in S and bulk polyA-containing pre-mRNA transcription taking place in G1 and G2. Thus, probes of 1 × 106 Daltons (constructed using sheared by sonication newly made methylated DNA filaments) revealed a modular organization in genes: after the hypermethylated promoter, they exhibited an alternation of unmethylated coding and methylated uncoding sequences. This encouraged the search for a language that genes regulated by methylation should have in common. An initial deciphering of restriction minimaps with hypomethylatable exons vs. hypermethylatable promoters and introns was improved when the bisulfite technique allowed a direct sequencing of m5C. In lymphocytes, where the transglutaminase gene is inactive, its promoter exhibited two fully methylated CpG-rich domains at 5’ and one fully unmethylated CpG-rich domain at 3’, including the site +1 and a 5’-UTR. At variance, in HUVEC cells, where the transglutaminase gene is active, in the first CpG-rich domain of promoter few doublets lost their –CH3. Such an inverse correlation suggested new hypotheses especially in connection with repair-modification: UV radiation would cause demethylation in given loci of a promoter by chance, whilst even a partial demethylation in this promoter would be able to resume a previously silent pre-mRNA transcription.展开更多
目的通过小样本外显子测序与公用数据库比对进行生物信息挖掘,探寻汉族人群高原红细胞增多症(high altitude polycythemia,HAPC)变异与发病的相关性。方法纳入汉族高原红细胞增多症男性患者4例和高原健康男性5例,采集静脉血并提取DNA进...目的通过小样本外显子测序与公用数据库比对进行生物信息挖掘,探寻汉族人群高原红细胞增多症(high altitude polycythemia,HAPC)变异与发病的相关性。方法纳入汉族高原红细胞增多症男性患者4例和高原健康男性5例,采集静脉血并提取DNA进行全外显子组测序;将测序数据进行功能学富集分析(gene ontology,GO&kyoto encyclopedia of genes and genomes,KEGG)构建突变基因蛋白质互作网络(protein protein interaction,PPI),选择显著性最高的基因,筛选潜在关键HAPC相关变异位点,初步探究相关变异与HAPC发病可能的机制。结果通过全外显子测序,发现HAPC相关的突变基因216个,其中表皮生长因子(epidemal growth farctor,EGF)基因在功能学富集分析(GO&KEGG),蛋白质互作网络(PPI)中具有高度显著性,初步筛选出5个潜在关键HAPC相关变异位点,通过生物信息学预测及分析,最终筛选出EGF基因上3个可能的变异c.2124G>A(p.Met708Ile)、c.2351A>T(p.Asp784Val)以及c.2759A>T(p.Glu920Val),可能是HAPC的突变位点,与HAPC发病相关。结论本研究表明汉族EGF基因的变异与HAPC发病存在相关性。EGF基因的变异可能通过干扰RNA剪接,改变RNA二级结构,影响蛋白质结构,进而影响EGF的生成及HAPC的发生发展。展开更多
In order to exploit the evolution and find novel low-molecular-weight glutenin subunit （LMW-GS） for improvement of common wheat quality, thirteen variants from a somatic hybrid introgression line II-12 between Triti...In order to exploit the evolution and find novel low-molecular-weight glutenin subunit （LMW-GS） for improvement of common wheat quality, thirteen variants from a somatic hybrid introgression line II-12 between Triticum aestivum cv. Jinan 177 （JN177） and Agropyron elongatum were characterized via genomic PCR. Four clones were pseudogenes because they contained an internal stop codon. The remaining nine variants contained intact open reading frames （ORFs）. Sequence alignment indicates that the proteins deduced from the nine ORFs have similar primary structure with LMW-GS cloned from its parents previously. However, they have some unique modifications in the structures. For example, EU292737 contains not only an extra Cys residue in the C-terminal domain but also a long repetitive domain. Both EU 159511 and EU292738 start their first Cys residue in the N-terminal repetitive domain, but not in the N-conserved domain traditionally. These structural alterations may have positive contributions to wheat flour quality. The results of phylogeny showed that most LMW-GS variances from 11-12 were homologous to those from parent JN177 and other wheat lines. The reason for quick evolution of LMW-GS in 11-12 was discussed.展开更多
Expressed sequence tags (ESTs), which have piled up considerably so far, provide a valuable resource for finding new genes, disease-relevant genes, and for recogniz- ing alternative splicing variants, SNP sites, etc. ...Expressed sequence tags (ESTs), which have piled up considerably so far, provide a valuable resource for finding new genes, disease-relevant genes, and for recogniz- ing alternative splicing variants, SNP sites, etc. The prereq- uisite for carrying out these researches is to correctly ascer- tain the gene-sequence-related ESTs. Based on analysis of the alignment results between some known gene sequences and ESTs in public database, several measures including Identity Check, Gap Check, Inclusion Check and Length Check have been introduced to judge whether an EST alignment is re- lated to a gene sequence or not. A computational program EDSAc1.0 has been developed to identify true EST align- ments and exon regions of query gene sequences. When tested with human gene sequences in the standard dataset HMR195 and evaluated with the standard measures of gene prediction performance, EDSAc1.0 can identify protein- coding regions with specificity of 0.997 and sensitivity of 0.88 at the nucleotide level, which outperform that of the coun- terpart TAP. A web server of EDSAc1.0 is available at http://infosci.hust.edu.cn.展开更多
报告中国汉族人群首例VAMP2基因突变致伴有肌张力低下的神经发育障碍和自闭症特征伴或不伴运动过度病(neurodevelopmental disorder with hypotonia and autistic features with or without hyperkinetic movements,NEDHAHM),以期为临...报告中国汉族人群首例VAMP2基因突变致伴有肌张力低下的神经发育障碍和自闭症特征伴或不伴运动过度病(neurodevelopmental disorder with hypotonia and autistic features with or without hyperkinetic movements,NEDHAHM),以期为临床诊治提供借鉴。患儿为14岁女童,以精神行为异常起病,表现为少言少语,基因检测提示VAMP2基因的3号外显子c.166C>T(p.Arg56Ter)杂合突变。对国外同类报告中12例患者资料回顾后发现,该病多在婴幼儿时期发病,男性多于女性,临床预后不佳,4-氨基吡啶可能为此病潜在性治疗药物,可改善患者症状。展开更多
文摘Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using complementary DNA (cDNA) derived from messenger RNA (mRNA) extracted from plant tissues and generated by reverse transcription. However, some CDS are difficult to acquire through this process as they are expressed at extremely low levels or have specific spatial and/or temporal expression patterns in vivo. These challenges require the development of alternative CDS cloning technologies. In this study, we found that the genomic intron-containing gene coding sequences (gDNA) from Arabidopsis thaliana, Oryza sativa, Brassica napus, and Glycine max can be correctly transcribed and spliced into mRNA in Nicotiana benthamiana. In contrast, gDNAs from Triticum aestivum and Sorghum bicolor did not function correctly. In transient expression experiments, the target DNA sequence is driven by a constitutive promoter. Theoretically, a sufficient amount of mRNA can be extracted from the N. benthamiana leaves, making it conducive to the cloning of CDS target genes. Our data demonstrate that N. benthamiana can be used as an effective host for the cloning CDS of plant genes.
文摘Using normal brain cell geneomic DNA as a template,transforming growth factor(TGFa)-IV exon gene was amplified by polymerase chain reaction(PCR). The sequence of amplified fragment was analysed with a DNA sequencing kit.The results showed that the cloned fragment is proved to be the TGFa-IV exon gene.
基金the Natural Science Foundation of Anhui Province,No.99044312(WY) and No.9741006(LX)Natural Science Foundation of Anhui Educational Commission,No.JL-97-077(WY).
文摘AIM: In hepatocellular carcinoma (HCC) prevalent areas of China, the point mutation of p53 exon7 is highly correlated with Hepatitis B virus(HBV) infection and aflatoxin B intake. While in non-HCC-prevalent areas of China, these factors are not so important in the etiology of HCC. Therefore, the point mutation of p53 exon7 may also be different than that in HCC-prevalent areas of China. The aim of this study is to investigate the status and carcinogenic role of the point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province, a non-HCC-prevalent area in China. METHODS: PCR PCR-SSCP and PCR-RFLP were applied to analyze the homozygous deletion and point mutation of p53 exon7 in HCC samples from Anhui, which were confirmed by DNA sequencing and Genbank comparison. RESULTS: In the 38 samples of hepatocellular carcinoma, no homozygous deletion of p53 exon7 was detected and point mutations of p53 exon7 were found in 4 cases, which were found to be heterozygous mutation of codon 249 with a mutation rate of 10.53%(4/38). The third base mutation(G-T) of p53 codon 249 was found by DNA sequencing and Genbank comparison. CONCLUSION: The incidence of point mutation of p53 codon 249 is lower in hepatocellular carcinoma and the heterozygous mutation of p53 exon7 found in these patients only indicate that they have genetic susceptibility to HCC. p53 codon 249 is a hotspot of p53 exon7 point mutation, suggesting that the point mutation of p53 exon 7 may not play a major role in the carcinogenesis of HCC in Anhui Province, a non-HCC-prevalent area in China.
文摘Summary: To examine the deletion and point mutation of WWOX (WW domain containing oxidoreductase) exons 6-8 in human non-small cell lung cancer and their possible relationship with pathological stages, tumor tissues and the corresponding normal tissues were obtained from 44 Chinese patients who had undergone surgery for non-small cell lung cancer. RNA was extracted from each sample and deletion and mutation of WWOX exons 6-8 were analyzed by RT-PCR and DNA sequencing. Our results showed that 28 of 44 (63.6 %) lung cancer samples showed loss of WWOX exons 6-8 transcript and the deletion was detected in only 3 of 44 (6.8 %) corresponding adjacent normal tissues (P<0.05). The transcript sequencing analyses of the 16 lung cancer samples without transcript loss of WWOX exons 6-8 revealed no difference from the sequence of GenBank. Moreover, the deletion of WWOX exons 6-8 was significantly higher in the smokers when compared with the non-smokers. It is also higher in the men and squamous carcinomas than in women and adenocarcinomas (P<0.05). The deletion, however, was not found to be associated with pathological stages of the tumors. Our study documented a high incidence of deletion of WWOX exons 6-8 in non-small cell lung cancer in Chinese patients and suggested that the frequent loss of WWOX exons 6-8 might play an important role in the tumorigenesis of non-small cell lung cancer in Chinese. WWOX exons 6-8 may serves as a candidate molecular target of smoking carcinogenesis, and point mutation is not a predominant way of alteration of WWOX exons 6-8.
文摘The pathways leading to synthesis and post-synthetic modification of DNA employed methionine as donor of atoms: the carbon that came from its –CH3 served for DNA replication and repair either in bacteria or humans;its entire –CH3 served instead for building N6-methyladenine and 5-methylcytosine on bacterial DNA and 5-methylcytosine alone on human DNA. In humans, although a slight extra-S asymmetric methylation appeared de novo yielding on parental DNA 5’-m5CpC-3’/ 3’-GpG-5’, 5’-m5CpT-3’/3’-GpA-5’ and 5’-m5CpA-3’/3’-GpT-5’ monomethylated dinucleotide pairs, a heavy symmetric methylation involved in S semiconservatively newly made DNA to guarantee genetic maintenance of –CH3 in 5’-m5CpG-3’/3’-Gpm5C-5’ dimethylated dinucleotide pairs. In this framework, an inverse correlation was found between bulk genomic DNA methylation occurring in S and bulk polyA-containing pre-mRNA transcription taking place in G1 and G2. Thus, probes of 1 × 106 Daltons (constructed using sheared by sonication newly made methylated DNA filaments) revealed a modular organization in genes: after the hypermethylated promoter, they exhibited an alternation of unmethylated coding and methylated uncoding sequences. This encouraged the search for a language that genes regulated by methylation should have in common. An initial deciphering of restriction minimaps with hypomethylatable exons vs. hypermethylatable promoters and introns was improved when the bisulfite technique allowed a direct sequencing of m5C. In lymphocytes, where the transglutaminase gene is inactive, its promoter exhibited two fully methylated CpG-rich domains at 5’ and one fully unmethylated CpG-rich domain at 3’, including the site +1 and a 5’-UTR. At variance, in HUVEC cells, where the transglutaminase gene is active, in the first CpG-rich domain of promoter few doublets lost their –CH3. Such an inverse correlation suggested new hypotheses especially in connection with repair-modification: UV radiation would cause demethylation in given loci of a promoter by chance, whilst even a partial demethylation in this promoter would be able to resume a previously silent pre-mRNA transcription.
文摘目的通过小样本外显子测序与公用数据库比对进行生物信息挖掘,探寻汉族人群高原红细胞增多症(high altitude polycythemia,HAPC)变异与发病的相关性。方法纳入汉族高原红细胞增多症男性患者4例和高原健康男性5例,采集静脉血并提取DNA进行全外显子组测序;将测序数据进行功能学富集分析(gene ontology,GO&kyoto encyclopedia of genes and genomes,KEGG)构建突变基因蛋白质互作网络(protein protein interaction,PPI),选择显著性最高的基因,筛选潜在关键HAPC相关变异位点,初步探究相关变异与HAPC发病可能的机制。结果通过全外显子测序,发现HAPC相关的突变基因216个,其中表皮生长因子(epidemal growth farctor,EGF)基因在功能学富集分析(GO&KEGG),蛋白质互作网络(PPI)中具有高度显著性,初步筛选出5个潜在关键HAPC相关变异位点,通过生物信息学预测及分析,最终筛选出EGF基因上3个可能的变异c.2124G>A(p.Met708Ile)、c.2351A>T(p.Asp784Val)以及c.2759A>T(p.Glu920Val),可能是HAPC的突变位点,与HAPC发病相关。结论本研究表明汉族EGF基因的变异与HAPC发病存在相关性。EGF基因的变异可能通过干扰RNA剪接,改变RNA二级结构,影响蛋白质结构,进而影响EGF的生成及HAPC的发生发展。
基金supported by the National High Technology Research and Development Program(No.2006AA10Z173 and 2006011001020)the Natural Science Foundation of Shandong Province(Y2007D48)
文摘In order to exploit the evolution and find novel low-molecular-weight glutenin subunit （LMW-GS） for improvement of common wheat quality, thirteen variants from a somatic hybrid introgression line II-12 between Triticum aestivum cv. Jinan 177 （JN177） and Agropyron elongatum were characterized via genomic PCR. Four clones were pseudogenes because they contained an internal stop codon. The remaining nine variants contained intact open reading frames （ORFs）. Sequence alignment indicates that the proteins deduced from the nine ORFs have similar primary structure with LMW-GS cloned from its parents previously. However, they have some unique modifications in the structures. For example, EU292737 contains not only an extra Cys residue in the C-terminal domain but also a long repetitive domain. Both EU 159511 and EU292738 start their first Cys residue in the N-terminal repetitive domain, but not in the N-conserved domain traditionally. These structural alterations may have positive contributions to wheat flour quality. The results of phylogeny showed that most LMW-GS variances from 11-12 were homologous to those from parent JN177 and other wheat lines. The reason for quick evolution of LMW-GS in 11-12 was discussed.
文摘Expressed sequence tags (ESTs), which have piled up considerably so far, provide a valuable resource for finding new genes, disease-relevant genes, and for recogniz- ing alternative splicing variants, SNP sites, etc. The prereq- uisite for carrying out these researches is to correctly ascer- tain the gene-sequence-related ESTs. Based on analysis of the alignment results between some known gene sequences and ESTs in public database, several measures including Identity Check, Gap Check, Inclusion Check and Length Check have been introduced to judge whether an EST alignment is re- lated to a gene sequence or not. A computational program EDSAc1.0 has been developed to identify true EST align- ments and exon regions of query gene sequences. When tested with human gene sequences in the standard dataset HMR195 and evaluated with the standard measures of gene prediction performance, EDSAc1.0 can identify protein- coding regions with specificity of 0.997 and sensitivity of 0.88 at the nucleotide level, which outperform that of the coun- terpart TAP. A web server of EDSAc1.0 is available at http://infosci.hust.edu.cn.
文摘报告中国汉族人群首例VAMP2基因突变致伴有肌张力低下的神经发育障碍和自闭症特征伴或不伴运动过度病(neurodevelopmental disorder with hypotonia and autistic features with or without hyperkinetic movements,NEDHAHM),以期为临床诊治提供借鉴。患儿为14岁女童,以精神行为异常起病,表现为少言少语,基因检测提示VAMP2基因的3号外显子c.166C>T(p.Arg56Ter)杂合突变。对国外同类报告中12例患者资料回顾后发现,该病多在婴幼儿时期发病,男性多于女性,临床预后不佳,4-氨基吡啶可能为此病潜在性治疗药物,可改善患者症状。
