排序方式: 共有74条查询结果,搜索用时 15 毫秒
41.
Sulem P Gudbjartsson DF Stacey SN Helgason A Rafnar T Jakobsdottir M Steinberg S Gudjonsson SA Palsson A Thorleifsson G Pálsson S Sigurgeirsson B Thorisdottir K Ragnarsson R Benediktsdottir KR Aben KK Vermeulen SH Goldstein AM Tucker MA Kiemeney LA Olafsson JH Gulcher J Kong A Thorsteinsdottir U Stefansson K 《Nature genetics》2008,40(7):835-837
We present results from a genome-wide association study for variants associated with human pigmentation characteristics among 5,130 Icelanders, with follow-up analyses in 2,116 Icelanders and 1,214 Dutch individuals. Two coding variants in TPCN2 are associated with hair color, and a variant at the ASIP locus shows strong association with skin sensitivity to sun, freckling and red hair, phenotypic characteristics similar to those affected by well-known mutations in MC1R. 相似文献
42.
Stacey SN Manolescu A Sulem P Rafnar T Gudmundsson J Gudjonsson SA Masson G Jakobsdottir M Thorlacius S Helgason A Aben KK Strobbe LJ Albers-Akkers MT Swinkels DW Henderson BE Kolonel LN Le Marchand L Millastre E Andres R Godino J Garcia-Prats MD Polo E Tres A Mouy M Saemundsdottir J Backman VM Gudmundsson L Kristjansson K Bergthorsson JT Kostic J Frigge ML Geller F Gudbjartsson D Sigurdsson H Jonsdottir T Hrafnkelsson J Johannsson J Sveinsson T Myrdal G Grimsson HN Jonsson T von Holst S 《Nature genetics》2007,39(7):865-869
Familial clustering studies indicate that breast cancer risk has a substantial genetic component. To identify new breast cancer risk variants, we genotyped approximately 300,000 SNPs in 1,600 Icelandic individuals with breast cancer and 11,563 controls using the Illumina Hap300 platform. We then tested selected SNPs in five replication sample sets. Overall, we studied 4,554 affected individuals and 17,577 controls. Two SNPs consistently associated with breast cancer: approximately 25% of individuals of European descent are homozygous for allele A of rs13387042 on chromosome 2q35 and have an estimated 1.44-fold greater risk than noncarriers, and for allele T of rs3803662 on 16q12, about 7% are homozygous and have a 1.64-fold greater risk. Risk from both alleles was confined to estrogen receptor-positive tumors. At present, no genes have been identified in the linkage disequilibrium block containing rs13387042. rs3803662 is near the 5' end of TNRC9 , a high mobility group chromatin-associated protein whose expression is implicated in breast cancer metastasis to bone. 相似文献
43.
Stuart PE Nair RP Ellinghaus E Ding J Tejasvi T Gudjonsson JE Li Y Weidinger S Eberlein B Gieger C Wichmann HE Kunz M Ike R Krueger GG Bowcock AM Mrowietz U Lim HW Voorhees JJ Abecasis GR Weichenthal M Franke A Rahman P Gladman DD Elder JT 《Nature genetics》2010,42(11):1000-1004
We carried out a meta-analysis of two recent psoriasis genome-wide association studies with a combined discovery sample of 1,831 affected individuals (cases) and 2,546 controls. One hundred and two loci selected based on P value rankings were followed up in a three-stage replication study including 4,064 cases and 4,685 controls from Michigan, Toronto, Newfoundland and Germany. In the combined meta-analysis, we identified three new susceptibility loci, including one at NOS2 (rs4795067, combined P = 4 × 10?11), one at FBXL19 (rs10782001, combined P = 9 × 10?1?) and one near PSMA6-NFKBIA (rs12586317, combined P = 2 × 10??). All three loci were also associated with psoriatic arthritis (rs4795067, combined P = 1 × 10??; rs10782001, combined P = 4 × 10??; and rs12586317, combined P = 6 × 1??) and purely cutaneous psoriasis (rs4795067, combined P = 1 × 10??; rs10782001, combined P = 2 × 10??; and rs12586317, combined P = 1 × 10??). We also replicated a recently identified association signal near RNF114 (rs495337, combined P = 2 × 10??). 相似文献
44.
以火箭式激振器为震源对高大结构物(即云南景洪澜沧江大桥主塔)进行了现场动力测试和分析,利用实测结构体系的动力特性,取得了场地土边界元参数,在考虑了土与结构相互作用的基础上,为选取全桥的抗震设计参数提供合理依据. 相似文献
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46.
通过构建以MDR1启动子为启动序列的荧光素酶报告基因载体,建立基于双荧光素酶报告基因系统的多药耐药抑制剂筛选模型。从HCT-8细胞中提取DNA并克隆含有MDR1基因启动子的序列。将该序列重组到荧光素酶报告基因载体pGL-3-Basic的启动区域中,从而构建报告基因载体pGL-MDR1。将pGL-MDR1和pRL-TK载体共转染到HCT-8和HCT-8/VCR细胞中,建立用于筛选多药耐药抑制剂的方法。通过调节不同载体的比例来优化转染效率。通过MDR1基因激活剂(热诱导)和抑制剂(EGCG)来验证该方法。通过直接测序法验证了pGL-MDR1含有MDR1基因启动子序列且没有出现碱基突变。在n(pGL-MDR1)∶n(pRL-TK)=5∶5时,转染效率最高并具有最高的荧光素酶活性。通过MDR1基因激活处理后表现为时间依赖性地激活MDR1基因的表达,而MDR1基因抑制剂的作用则相反。 相似文献
47.
克隆了酿酒酵母(Saccharomyces cerevisiae) 中的3-磷酸甘油脱氢酶和3-磷酸甘油酯酶基因,通过融合PCR构建了双基因共表达载体,将酵母细胞内应答渗透压变化的甘油合成途径引入大肠杆菌(Escherichia coli)。以葡萄糖为底物对重组大肠杆菌进行摇瓶发酵培养,该重组菌的甘油产量为1g/L。渗透压胁迫测试证明该重组菌的耐渗透压性能较出发菌株有明显提高。 相似文献
48.
基于能带结构,提出Jahn-Teller效应的诱发条件.基于声子色散曲线,揭示晶格动态稳定性和简并振动模式产生劈裂的物理特征.基于电子局域化函数和束缚能,揭示原子成键特性.结果表明,TM-Zn(TM=Ni,Pd,Pt,Cu,Ag,Au)金属间化合物发生立方到四方的相变变形过程中,结构保持稳定. 相似文献
49.
沙平 《厦门理工学院学报》2000,(2)
科学研究离不开分类 ,本文通过对汉语中最基本的语法单位语素的分类研究 ,不仅准确地定义了汉语虚词 ,而且理清了汉语语法研究中长期混淆不清的两个概念———汉语虚语与附加成分的界限 相似文献
50.
Kong A Thorleifsson G Gudbjartsson DF Masson G Sigurdsson A Jonasdottir A Walters GB Jonasdottir A Gylfason A Kristinsson KT Gudjonsson SA Frigge ML Helgason A Thorsteinsdottir U Stefansson K 《Nature》2010,467(7319):1099-1103
Meiotic recombinations contribute to genetic diversity by yielding new combinations of alleles. Recently, high-resolution recombination maps were inferred from high-density single-nucleotide polymorphism (SNP) data using linkage disequilibrium (LD) patterns that capture historical recombination events. The use of these maps has been demonstrated by the identification of recombination hotspots and associated motifs, and the discovery that the PRDM9 gene affects the proportion of recombinations occurring at hotspots. However, these maps provide no information about individual or sex differences. Moreover, locus-specific demographic factors like natural selection can bias LD-based estimates of recombination rate. Existing genetic maps based on family data avoid these shortcomings, but their resolution is limited by relatively few meioses and a low density of markers. Here we used genome-wide SNP data from 15,257 parent-offspring pairs to construct the first recombination maps based on directly observed recombinations with a resolution that is effective down to 10 kilobases (kb). Comparing male and female maps reveals that about 15% of hotspots in one sex are specific to that sex. Although male recombinations result in more shuffling of exons within genes, female recombinations generate more new combinations of nearby genes. We discover novel associations between recombination characteristics of individuals and variants in the PRDM9 gene and we identify new recombination hotspots. Comparisons of our maps with two LD-based maps inferred from data of HapMap populations of Utah residents with ancestry from northern and western Europe (CEU) and Yoruba in Ibadan, Nigeria (YRI) reveal population differences previously masked by noise and map differences at regions previously described as targets of natural selection. 相似文献