Objective： Nonsyndromic cleft lip with or without cleft palate（NSCL/P） is a common birth defect with unclear etiology. Both genetic and environmental factors may contribute to NSCL/P. Many genes have been identifie...Objective： Nonsyndromic cleft lip with or without cleft palate（NSCL/P） is a common birth defect with unclear etiology. Both genetic and environmental factors may contribute to NSCL/P. Many genes have been identified as candidate genes associated with this disease. Interferon regulatory factor 6（IRF6） gene and transforming growth factor-a（TGFA） gene seem to be crucial in the predisposition of NSCL/ P. Here we evaluated some single nucleotide polymorphisms（SNPs） loci of TGFA and IRF6 genes in Chinese nuclear families consisting of fathers, mothers and affected offspring with NSCL/P. Methods：Fifty patients of NSCL/P were confirmed by the plastic surgeons. They and their parents were included in the study, all with the informed consents. SNPs loci of TGFA and IRF6 genes were analyzed by microarray technology. Some PCR products were randomly chosen and sequenced to check microarray results. The distribution of gene type and allele frequency between patient group and parents group were compared. Then a Haplotype Relative Risk（HRR） and Transmission Disequilibrium Test（TDT） were performed. Results：The sequences of randomly selected PCR products were all consistent with the microarray results. All loci were in Hardy-Weinberg equilibrium. There were no significant differences in the distribution of genotypes and alleles between patients and their parents. Using HRR and TDT analyses the V274I of IRF6 was associated with NSCL/P, while another SNP locus oflRF6 was not. Strong evidence of linkage disequilibrium was found between the 2 SNP loci of TGFA and disease with the HRR analysis, but not with the TDT analysis. Conclusion：Our study confirms the contribution of IRF6 in the etiology of NSCL/P in populations of Asian ancestry. The association of TGFA with NSCL/P requires further research.展开更多
Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with th...Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymorphism of MMP-9 or the A1/A2 polymorphism of p53 gcne with the risk of no-small-cell lung cancer（NSCLC） in Han population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore, the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.展开更多
The value of crop wild relatives has long been acknowledged and this wild resource has been used to improve crop performance with clear economic benefits. Sugar beet (Beta vulgaris subsp. vulgaris) is the most economi...The value of crop wild relatives has long been acknowledged and this wild resource has been used to improve crop performance with clear economic benefits. Sugar beet (Beta vulgaris subsp. vulgaris) is the most economically valuable crop species in the order Caryophyllales, B. vulgaris subsp. maritima being the ancestor of the cultivated beets. The wild species of the genus Beta s.l. are commonly found in coastal areas of Europe and Mediterranean Region, where a rich genetic heritage still exists. Broadening the genetic base of sugar beet by introgression with wild relatives is a growing need regarding the maintenance of ecologically important traits. Since wild relatives have adapted to specific habitats, they constitute an important source of novel traits for the beet breeding pool. So, we conducted a broader research project aiming to delimit taxa and identify priority locations to establish genetic reserves of the wild Beta species occurring in Portugal (Western Iberian Peninsula). The aim of this study was: 1) to identify and characterize the main habitats of these wild Beta species;and 2) to present a review of some genetic tools available for future application in sugar beet breeding. In this review, we have focused on EcoTILLING as a molecular tool to assess DNA polymerphisms in wild populations of Beta and identify candidate genes related to drought and salt tolerance, as well as addressed some issues related to next-generation sequencing (NGS) technologies as a new molecular tool to assess adaptive genetic variation on the wild relatives of sugar beet.展开更多
The majority of single nucleotide polymorphisms(SNPs)found in the coding region(cSNPs)are single base substitutions that may or may not lead to amino acid substitutions,most of which are related to diseases.Some cSNPs...The majority of single nucleotide polymorphisms(SNPs)found in the coding region(cSNPs)are single base substitutions that may or may not lead to amino acid substitutions,most of which are related to diseases.Some cSNPs may prove useful for their potential links to functional cSNPs via linkage disequilibrium mapping.We have selected 48 cSNPs located in the coding regions of 25 genes to construct the cSNP chip.These genes are harbored in the high frequency loss regions of the chromosome 1p and 8p and related with apoptosis,cell cycles,signal transduction,oncogene,tumor suppressor genes and so on.All of the cSNPs can lead to amino acid substitutions except TP73(rs1801174).The PCR products amplified from 31 hepatocellular carcinoma(HCC)specimens were labeled with Dig-dUTP and then hybridized with the cSNP chips.The results showed that there was no hybridization signal when there was more than one site of mutation in the amplification sequence,indicating that the cSNP chip had a high sensitivity.The statistic data of the SNP(MT,homozygous and HT,heterozygous)in the HCC patients with different phenotypes(HBV+/-,differentiation stage,family history positive or negative,tumor size)indicated that the number of MT was distinctly different between patients with positive HBV and negative HBV.The MT and HT numbers of all the 48 cSNPs were significantly different between low differentiation and high differentiation HCC patients.The numbers of MT and HT were not different between positived and negative family history groups and between tumor size>3 cm and≤3 cm groups.The study results provided useful information for understanding the molecular mechanisms of HCC development.展开更多
目的探讨Nod样受体家族蛋白3(Nod-like receptor protein 3,NLRP3)rs4612666及rs7525979位点多态性与中国北方东部汉族人群帕金森病(Parkinson disease,PD)发病风险的相关性。方法采用病例对照研究,共招募400例PD患者(PD组)及400例健康...目的探讨Nod样受体家族蛋白3(Nod-like receptor protein 3,NLRP3)rs4612666及rs7525979位点多态性与中国北方东部汉族人群帕金森病(Parkinson disease,PD)发病风险的相关性。方法采用病例对照研究,共招募400例PD患者(PD组)及400例健康对照者(对照组),应用聚合酶链反应-限制性片段长度多态性方法鉴定NLRP3基因SNPs位点rs4612666和rs7525979。结果PD组rs4612666等位基因与对照组具有统计学差异,C等位基因频率低于对照组,降低发病风险(OR=0.794,95%CI:0.653~0.967,P=0.021),隐性遗传模型CC/TT+CT分布在PD组与对照组之间差异具有统计学意义(OR=0.667,95%CI:0.481~0.925,P=0.015)。亚组分析中,与对照组比较,女性PD组与早发型PD组等位基因分布差异具有统计学意义(P=0.003,P=0.018)。rs7525979位点的基因型分布和等位基因频率在PD组与对照组比较均无统计学差异(P>0.05)。结论在中国北方东部汉族人群中,NLRP3 rs4612666的C等位基因是PD的保护性因素。展开更多
Enhancers are often mutated and dysregulated in various diseases such as cancer.By integrating the function annotation of the mammalian genome(FANTOM)enhancers expression profiles and RNA-seq data from The Cancer Geno...Enhancers are often mutated and dysregulated in various diseases such as cancer.By integrating the function annotation of the mammalian genome(FANTOM)enhancers expression profiles and RNA-seq data from The Cancer Genome Atlas(TCGA)of 13 cancers and their corresponding para-cancerous tissues,we systematically identified a total of 4702 significantly differentially expressed(DE)enhancers.Furthermore,a total of 1036 DE genes regulated by DE enhancerswere identified.Itwas found that in these 13 cancers,most(61.13%)enhancers were ubiquitously expressed,whereas DE enhancers were more likely to be tissue-specific expressed,and the DE genes regulated by DE enhancers were significantly enriched in cancer-related pathways.Finally,it was manifested that 74 single nucleotide polymorphisms(SNPs)were located in 37 DE enhancers,and these SNPs affected the gain and loss of functional transcription factor binding sites of 758 transcription factors,which were shown to be highly correlated with tumorigenesis and development.展开更多
There is a rapidly rising trend in the development and application of molecular marker assays for gene map- ping and discovery in field crops and trees. Thus far, more than 50 SNP arrays and 15 different types of geno...There is a rapidly rising trend in the development and application of molecular marker assays for gene map- ping and discovery in field crops and trees. Thus far, more than 50 SNP arrays and 15 different types of genotyping-by-sequencing （GBS） platforms have been developed in over 25 crop species and perennial trees. However, much less effort has been made on developing ultra-high-throughput and cost-effective genotyping platforms for applied breeding programs. In this review, we discuss the scientific bottlenecks in existing SNP arrays and GBS technologies and the strategies to develop targeted platforms for crop mo- lecular breeding. We propose that future practical breeding platforms should adopt automated genotyping technologies, either array or sequencing based, target functional polymorphisms underpinning economic traits, and provide desirable prediction accuracy for quantitative traits, with universal applications under wide genetic backgrounds in crops. The development of such platforms faces serious challenges at both the technological level due to cost ineffectiveness, and the knowledge level due to large genotype- phenotype gaps in crop plants. It is expected that such genotyping platforms will be achieved in the next ten years in major crops in consideration of （a） rapid development in gene discovery of important traits, （b） deepened understanding of quantitative traits through new analytical models and population designs, （c） integration of multi-layer -omics data leading to identification of genes and pathways responsible for important breeding traits, and （d） improvement in cost effectiveness of large-scale genotyping. Crop breeding chips and genotyping platforms will provide unprecedented opportunities to accelerate the development of cultivars with desired yield potential, quality, and enhanced adaptation to mitigate the effects of climate change.展开更多
A high-density single nucleotide polymorphism （SNP） array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technolog...A high-density single nucleotide polymorphism （SNP） array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technologies for accurate SNP detection, it is possible to design high-density and high-quality rice SNP arrays. Here we report the devel- opment of a high-density rice SNP array and its utility. SNP probes were designed by screening more than 10 000 000 SNP loci extracted from the re-sequencing data of 801 rice varieties and an array named RiceSNP50 was produced on the Illumina Infinium platform. The array contained 51 478 evenly distributed markers, 68% of which were within genic regions. Several hundred rice plants with parent/F1 relationships were used to generate a high-quality cluster file for accurate SNP calling. Application tests showed that this array had high genotyping accuracy, and could be used for dif- ferent objectives. For example, a core collection of elite rice varieties was clustered with fine resolution. Genome-wide association studies （GWAS） analysis correctly identified a characterized QTL. Further, this array was successfully used for variety verification and trait introgression. As an accurate high-throughput genotyping tool, RiceSNP50 will play an important role in both functional genomics studies and molecular breeding.展开更多
Single nucleotide polymorphisms （SNPs） are the most abundant sequence variations found in plant genomes and are widely used as molecular genetic markers in cultivar identification and genetic diversity studies. The ...Single nucleotide polymorphisms （SNPs） are the most abundant sequence variations found in plant genomes and are widely used as molecular genetic markers in cultivar identification and genetic diversity studies. The objective of this study was to identify SNP markers useful for discrimination of citrus cultivars, since large numbers of expressed sequence tags （ESTs） of sweet orange are available from the National Center for Biotechnology Information （NCBI）. We now have the opportunity to discover SNP markers suitable for determining the haplotypes with which to distinguish very closely related cultivars and to assess genetic diversity within or between related species of citrus. SNPs and small insertions/deletions （Indels） from ESTs of sweet orange and satsuma were identified by the in silico SNP discovery strategy. 55 296 EST sequences of sweet orange and 2 575 of satsuma retrieved from the NCBI repository were mined for potential SNPs. Cleaved amplified polymorphic sequences （CAPS） and sequencing approaches were used to validate putative SNPs in a sample of 30 citrus accessions. A total of 3 348 putative SNPs were identified based on the abundance of sequences and haplotype cosegregation. Of these 3 348 SNPs, the transitions, transversions and Indels ratios were 47.9, 36.1 and 16.0%, respectively. The SNPs occurred on average at a frequency of 1 per 164 bp in the coding region of citrus. 14 SNPs were randomly selected and genotyped according to 30 citrus accessions including 23 accessions of sweet orange; 11 SNPs displayed polymorphism with an average polymorphism information content （PIC） of 0.20 among 30 citrus accessions. The genetic diversity present in sweet orange was low, so the 14 SNP markers failed to discriminate different cultivars of sweet orange, but they did succeed in distinguishing accessions of inter-species of citrus. In this study, SNPs were mined from EST sequences of sweet orange and satsuma, which displayed potential capability as molecular markers to discriminate in展开更多
Prostate cancer （PCa） research in China has been on a rocketing trend in recent years. The first genome-wide association study （GWAS） in China identified two new PCa risk associated single nucleotide polymorphisms...Prostate cancer （PCa） research in China has been on a rocketing trend in recent years. The first genome-wide association study （GWAS） in China identified two new PCa risk associated single nucleotide polymorphisms （SNPs）. Next generation sequencing is beginning to be used, yielding novel findings： gene fusions, long non-coding RNAs and other variations. Mechanisms of PCa progression have been illustrated while various diagnosis biomarkers have been investigated extensively. Personalized therapy based on genetic factors, nano-medicine and traditional Chinese medicine has been the focus of experimental therapeutic research for PCa. This review intends to shed light upon the recent progress in PCa research in China and points out the possible breakthroughs in the future.展开更多
With completion of the Populus genome sequencing project and the availability of many expressed sequence tags （ESTs） databases in forest trees, attention is now rapidly shifting towards the study of individual genet...With completion of the Populus genome sequencing project and the availability of many expressed sequence tags （ESTs） databases in forest trees, attention is now rapidly shifting towards the study of individual genetic variation in natural populations. The most abundant form of genetic variation in many eukaryotic species is represented by single nucleotide polymorphisms （SNPs）, which can account for heritable inter-individual differences in complex phenotypes. Unlike humans, the linkage disequilibrium （LD） rapidly decays within candidate genes in forest trees. Thus, SNPs-based candidate gene association studies are considered to be a most effective approach to dissect the complex quantitative traits in forest trees. The present study demonstrates that LD mapping can be used to identify alleles associated with quantitative traits and suggests that this new approach could be particularly useful for performing breeding programs in forest trees. In this review, we will describe the fundamentals, patterns of SNPs distribution and frequency, summarize recent advances in SNPs discovery and LD and comment on the application of LD in the dissection of complex quantitative traits in forest tress. We also put forward the outlook for future SNPs-based association analysis of quantitative traits in forest trees.展开更多
基金supported by the Medical Technology Development Foundation of Jiangsu Provincial Health Bureau of China (H200513)Changjiang Scholars and Innovative Research Team in University (IRT0631) and National 973 Program(2006CB944005)
文摘Objective： Nonsyndromic cleft lip with or without cleft palate（NSCL/P） is a common birth defect with unclear etiology. Both genetic and environmental factors may contribute to NSCL/P. Many genes have been identified as candidate genes associated with this disease. Interferon regulatory factor 6（IRF6） gene and transforming growth factor-a（TGFA） gene seem to be crucial in the predisposition of NSCL/ P. Here we evaluated some single nucleotide polymorphisms（SNPs） loci of TGFA and IRF6 genes in Chinese nuclear families consisting of fathers, mothers and affected offspring with NSCL/P. Methods：Fifty patients of NSCL/P were confirmed by the plastic surgeons. They and their parents were included in the study, all with the informed consents. SNPs loci of TGFA and IRF6 genes were analyzed by microarray technology. Some PCR products were randomly chosen and sequenced to check microarray results. The distribution of gene type and allele frequency between patient group and parents group were compared. Then a Haplotype Relative Risk（HRR） and Transmission Disequilibrium Test（TDT） were performed. Results：The sequences of randomly selected PCR products were all consistent with the microarray results. All loci were in Hardy-Weinberg equilibrium. There were no significant differences in the distribution of genotypes and alleles between patients and their parents. Using HRR and TDT analyses the V274I of IRF6 was associated with NSCL/P, while another SNP locus oflRF6 was not. Strong evidence of linkage disequilibrium was found between the 2 SNP loci of TGFA and disease with the HRR analysis, but not with the TDT analysis. Conclusion：Our study confirms the contribution of IRF6 in the etiology of NSCL/P in populations of Asian ancestry. The association of TGFA with NSCL/P requires further research.
文摘Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymorphism of MMP-9 or the A1/A2 polymorphism of p53 gcne with the risk of no-small-cell lung cancer（NSCLC） in Han population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore, the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.
基金supported by the Portuguese Foundation for Science and Technology with the FCT/Ciência 2008 to DB and MMREcologi-cal data presented is an output from the project PTDC/AGR-AAM/73144/2006 funded by the Portuguese Foundation for Science and Technology.
文摘The value of crop wild relatives has long been acknowledged and this wild resource has been used to improve crop performance with clear economic benefits. Sugar beet (Beta vulgaris subsp. vulgaris) is the most economically valuable crop species in the order Caryophyllales, B. vulgaris subsp. maritima being the ancestor of the cultivated beets. The wild species of the genus Beta s.l. are commonly found in coastal areas of Europe and Mediterranean Region, where a rich genetic heritage still exists. Broadening the genetic base of sugar beet by introgression with wild relatives is a growing need regarding the maintenance of ecologically important traits. Since wild relatives have adapted to specific habitats, they constitute an important source of novel traits for the beet breeding pool. So, we conducted a broader research project aiming to delimit taxa and identify priority locations to establish genetic reserves of the wild Beta species occurring in Portugal (Western Iberian Peninsula). The aim of this study was: 1) to identify and characterize the main habitats of these wild Beta species;and 2) to present a review of some genetic tools available for future application in sugar beet breeding. In this review, we have focused on EcoTILLING as a molecular tool to assess DNA polymerphisms in wild populations of Beta and identify candidate genes related to drought and salt tolerance, as well as addressed some issues related to next-generation sequencing (NGS) technologies as a new molecular tool to assess adaptive genetic variation on the wild relatives of sugar beet.
文摘The majority of single nucleotide polymorphisms(SNPs)found in the coding region(cSNPs)are single base substitutions that may or may not lead to amino acid substitutions,most of which are related to diseases.Some cSNPs may prove useful for their potential links to functional cSNPs via linkage disequilibrium mapping.We have selected 48 cSNPs located in the coding regions of 25 genes to construct the cSNP chip.These genes are harbored in the high frequency loss regions of the chromosome 1p and 8p and related with apoptosis,cell cycles,signal transduction,oncogene,tumor suppressor genes and so on.All of the cSNPs can lead to amino acid substitutions except TP73(rs1801174).The PCR products amplified from 31 hepatocellular carcinoma(HCC)specimens were labeled with Dig-dUTP and then hybridized with the cSNP chips.The results showed that there was no hybridization signal when there was more than one site of mutation in the amplification sequence,indicating that the cSNP chip had a high sensitivity.The statistic data of the SNP(MT,homozygous and HT,heterozygous)in the HCC patients with different phenotypes(HBV+/-,differentiation stage,family history positive or negative,tumor size)indicated that the number of MT was distinctly different between patients with positive HBV and negative HBV.The MT and HT numbers of all the 48 cSNPs were significantly different between low differentiation and high differentiation HCC patients.The numbers of MT and HT were not different between positived and negative family history groups and between tumor size>3 cm and≤3 cm groups.The study results provided useful information for understanding the molecular mechanisms of HCC development.
基金This work was supported by Basic Research Cultivation Support Programof Fundamental Research Funds for the Central Universities(Grant No.2682021ZTPY016)the National Science and Technology Major Project of Infectious Diseases(Grant No.R111320H01004).
文摘Enhancers are often mutated and dysregulated in various diseases such as cancer.By integrating the function annotation of the mammalian genome(FANTOM)enhancers expression profiles and RNA-seq data from The Cancer Genome Atlas(TCGA)of 13 cancers and their corresponding para-cancerous tissues,we systematically identified a total of 4702 significantly differentially expressed(DE)enhancers.Furthermore,a total of 1036 DE genes regulated by DE enhancerswere identified.Itwas found that in these 13 cancers,most(61.13%)enhancers were ubiquitously expressed,whereas DE enhancers were more likely to be tissue-specific expressed,and the DE genes regulated by DE enhancers were significantly enriched in cancer-related pathways.Finally,it was manifested that 74 single nucleotide polymorphisms(SNPs)were located in 37 DE enhancers,and these SNPs affected the gain and loss of functional transcription factor binding sites of 758 transcription factors,which were shown to be highly correlated with tumorigenesis and development.
基金This study was supported by the National Key Research and Development Program of China （2016YFD0101802 and 2016YFE0108600） and National Natural Science Foundation of China （31550110212）.
文摘There is a rapidly rising trend in the development and application of molecular marker assays for gene map- ping and discovery in field crops and trees. Thus far, more than 50 SNP arrays and 15 different types of genotyping-by-sequencing （GBS） platforms have been developed in over 25 crop species and perennial trees. However, much less effort has been made on developing ultra-high-throughput and cost-effective genotyping platforms for applied breeding programs. In this review, we discuss the scientific bottlenecks in existing SNP arrays and GBS technologies and the strategies to develop targeted platforms for crop mo- lecular breeding. We propose that future practical breeding platforms should adopt automated genotyping technologies, either array or sequencing based, target functional polymorphisms underpinning economic traits, and provide desirable prediction accuracy for quantitative traits, with universal applications under wide genetic backgrounds in crops. The development of such platforms faces serious challenges at both the technological level due to cost ineffectiveness, and the knowledge level due to large genotype- phenotype gaps in crop plants. It is expected that such genotyping platforms will be achieved in the next ten years in major crops in consideration of （a） rapid development in gene discovery of important traits, （b） deepened understanding of quantitative traits through new analytical models and population designs, （c） integration of multi-layer -omics data leading to identification of genes and pathways responsible for important breeding traits, and （d） improvement in cost effectiveness of large-scale genotyping. Crop breeding chips and genotyping platforms will provide unprecedented opportunities to accelerate the development of cultivars with desired yield potential, quality, and enhanced adaptation to mitigate the effects of climate change.
基金grants from the National High Technology Research and Development Program of China，the National Program on Key Basic Research Project of China，the National Natural Science Foundation of China，Guangdong Innovative Research Team Program，the Ministry of Agriculture of China
文摘A high-density single nucleotide polymorphism （SNP） array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technologies for accurate SNP detection, it is possible to design high-density and high-quality rice SNP arrays. Here we report the devel- opment of a high-density rice SNP array and its utility. SNP probes were designed by screening more than 10 000 000 SNP loci extracted from the re-sequencing data of 801 rice varieties and an array named RiceSNP50 was produced on the Illumina Infinium platform. The array contained 51 478 evenly distributed markers, 68% of which were within genic regions. Several hundred rice plants with parent/F1 relationships were used to generate a high-quality cluster file for accurate SNP calling. Application tests showed that this array had high genotyping accuracy, and could be used for dif- ferent objectives. For example, a core collection of elite rice varieties was clustered with fine resolution. Genome-wide association studies （GWAS） analysis correctly identified a characterized QTL. Further, this array was successfully used for variety verification and trait introgression. As an accurate high-throughput genotyping tool, RiceSNP50 will play an important role in both functional genomics studies and molecular breeding.
基金supported by the National Natural Science Foundation of China(2006BAD13B06-1-4)the Natural Science Foundation of Chongqing,China (CSTC,2007BB1343)
文摘Single nucleotide polymorphisms （SNPs） are the most abundant sequence variations found in plant genomes and are widely used as molecular genetic markers in cultivar identification and genetic diversity studies. The objective of this study was to identify SNP markers useful for discrimination of citrus cultivars, since large numbers of expressed sequence tags （ESTs） of sweet orange are available from the National Center for Biotechnology Information （NCBI）. We now have the opportunity to discover SNP markers suitable for determining the haplotypes with which to distinguish very closely related cultivars and to assess genetic diversity within or between related species of citrus. SNPs and small insertions/deletions （Indels） from ESTs of sweet orange and satsuma were identified by the in silico SNP discovery strategy. 55 296 EST sequences of sweet orange and 2 575 of satsuma retrieved from the NCBI repository were mined for potential SNPs. Cleaved amplified polymorphic sequences （CAPS） and sequencing approaches were used to validate putative SNPs in a sample of 30 citrus accessions. A total of 3 348 putative SNPs were identified based on the abundance of sequences and haplotype cosegregation. Of these 3 348 SNPs, the transitions, transversions and Indels ratios were 47.9, 36.1 and 16.0%, respectively. The SNPs occurred on average at a frequency of 1 per 164 bp in the coding region of citrus. 14 SNPs were randomly selected and genotyped according to 30 citrus accessions including 23 accessions of sweet orange; 11 SNPs displayed polymorphism with an average polymorphism information content （PIC） of 0.20 among 30 citrus accessions. The genetic diversity present in sweet orange was low, so the 14 SNP markers failed to discriminate different cultivars of sweet orange, but they did succeed in distinguishing accessions of inter-species of citrus. In this study, SNPs were mined from EST sequences of sweet orange and satsuma, which displayed potential capability as molecular markers to discriminate in
基金This work was supported by grants from the National Basic Research Program of China （No. 2012CD518300）, the National Natural Science Foundation of China （No. 81101946）, and the Prostate Cancer Foundation Young Investigator Award, and Shanghai Pujiang Program （12PJD008）.
文摘Prostate cancer （PCa） research in China has been on a rocketing trend in recent years. The first genome-wide association study （GWAS） in China identified two new PCa risk associated single nucleotide polymorphisms （SNPs）. Next generation sequencing is beginning to be used, yielding novel findings： gene fusions, long non-coding RNAs and other variations. Mechanisms of PCa progression have been illustrated while various diagnosis biomarkers have been investigated extensively. Personalized therapy based on genetic factors, nano-medicine and traditional Chinese medicine has been the focus of experimental therapeutic research for PCa. This review intends to shed light upon the recent progress in PCa research in China and points out the possible breakthroughs in the future.
文摘With completion of the Populus genome sequencing project and the availability of many expressed sequence tags （ESTs） databases in forest trees, attention is now rapidly shifting towards the study of individual genetic variation in natural populations. The most abundant form of genetic variation in many eukaryotic species is represented by single nucleotide polymorphisms （SNPs）, which can account for heritable inter-individual differences in complex phenotypes. Unlike humans, the linkage disequilibrium （LD） rapidly decays within candidate genes in forest trees. Thus, SNPs-based candidate gene association studies are considered to be a most effective approach to dissect the complex quantitative traits in forest trees. The present study demonstrates that LD mapping can be used to identify alleles associated with quantitative traits and suggests that this new approach could be particularly useful for performing breeding programs in forest trees. In this review, we will describe the fundamentals, patterns of SNPs distribution and frequency, summarize recent advances in SNPs discovery and LD and comment on the application of LD in the dissection of complex quantitative traits in forest tress. We also put forward the outlook for future SNPs-based association analysis of quantitative traits in forest trees.
