8 resultados para genetic association study

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Introduction. The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to associate with human longevity. However, little information is available in a Han Chinese longevity Population. Therefore, we investigat

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随着人口老龄化的发展,对衰老和长寿的研究越来越受到关注。科学家们希望找到衰老相关疾病的致病机理以及治疗手段,从而降低这些疾病的发病风险,减少社会和经济负担。长寿老人受衰老相关疾病的困扰相对较少,自然成为研究的热点人群。而由于长寿的遗传力相对较高,关于长寿的遗传学研究也成为这个领域的热点之一。作为在从无脊椎动物到脊椎动物中一条非常保守的信号通路,胰岛素/胰岛素样生长因子1(IIS)信号通路是一条与生长发育代谢密切相关的信号通路。同时,在模式生物的研究中发现,减弱这条信号通路会导致模式生物寿命的延长。而在人类群体的相关性研究中,这条通路上一些基因的遗传变异位点与长寿、血清胰岛素样生长因子1(IGF1)水平以及一些衰老相关疾病如糖尿病、癌症和心脑血管疾病相关。为了探讨IIS信号通路上一些基因的遗传变异与长寿的关系,本研究在中国四川省都江堰市招募了共493名无相互关系的长寿老人,其中男性252人,年龄均大于90岁,女性241人,年龄均大于94岁。同时,在该地区招募了442名年轻的对照个体,年龄在22岁到73岁之间。我们对IIS信号通路上的一些基因的遗传变异位点利用测序,片段分析,RFLP等方法进行了扫描。包括(1)IGF1基因启动子区域及内含子1中的一个微卫星位点;(2)IGF1R基因外显子序列中的4个变异位点,包括3个SNP和一个2碱基缺失位点;(3)FOXO3A基因内含子1中的3个SNP位点。本研究发现,在该人群中,IGF1基因启动子区域的遗传变异与长寿没有相关性,但携带该区域中的微卫星位点18/21基因型的男性个体在长寿群体中所占比例高于在对照群体中所占的比例(11.11 vs. 5.45%, p=0.011)。虽然经过多重检验校正后显著性消失了,但考虑到这个位点曾被报道与多种衰老相关疾病相关,因此,这个位点不是影响长寿的潜在功能位点,但有可能与真正的潜在功能位点相连锁,这一观点有待进一步研究的验证。本研究并没有发现IGF1R基因外显子序列中的遗传变异与长寿存在相关性。同时,研究结果支持FOXO3A基因的遗传变异与长寿相关,这样,继日籍美国人,德国人,意大利人群体后,在中国汉族人群中也证实了这一结果。同时,在FOXO3A基因上的一个未报道过的单核苷酸多态性(SNP)位点(109080595)在本研究中被发现,携带这个基因突变纯和基因型的个体仅在长寿人群中出现(8/492 vs. 0/414, 基因型分布差异p值为0.011)。关于FOXO3A基因的功能以及新发现位点在其他群体中的基因型分布情况值得进一步深入研究。综上所述,本研究第一次在中国汉族人群中对IIS信号通路的一些基因的遗传变异与长寿的相关性进行了探讨,更多群体及更大样本量的研究有助于加深对长寿遗传机制的认识。

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随着社会的进步和医疗卫生水平的不断提高,人类获得了更高的平均寿 命,很多国家都步入了老龄化社会的行列。由于长寿具有遗传的倾向,所以 科学家们致力于人类长寿及衰老性疾病发生机理的研究,目的是为了使人类 在获得更长寿命的同时能够抵御或减缓老年性疾病的侵袭,远离衰老带来的 困扰,享受高质量的生活。 线粒体是真核生物的重要细胞器,具有长度为约为16569bp 的环状 DNA 分子。在人类群体,特别是欧洲群体的相关性研究中,线粒体DNA (mtDNA)编码区和控制区的一些多态性位点显示出与长寿及衰老性疾病的 相关。特别是mtDNA 控制区的C150T 变异除了在多个长寿人群中富集之外, 更是具有改变mtDNA 重链复制起始位点的功能。 为了探讨mtDNA 控制区多态性位点与中国汉族长寿人群是否存在相关 性,本研究在中国四川省都江堰地区采集了556 名年龄90 至108 岁的互无 关系的长寿老人血液样本,其中男性202 名,女性354 名。同时还采集了 214 名长寿老人的亲属和312 名无关对照的血液样本,年龄分别在10 至69 岁之间和22 到73 岁之间。我们对这些样本的mtDNA 通过测序和RFLP 等 手段进行了扫描,采集并记录了mtDNA 单倍型类群信息和控制区位点多态 信息。 在该人群中,本研究发现mtDNA 的主要单倍型类群与长寿没有显著的 相关性,总体单倍型类群频率分布在三个组别中基本一致(p=0.318)。对 mtDNA 控制区C150T 变异的频率在三个组别中做了包括总体频率差异,区 分mtDNA 单倍型类群的频率差异,区分样本性别的频率差异以及mtDNA 单倍型类群与性别信息联合的频率差异的分析。虽然在个别的比较中得到了 显著差异,但经过多重检验校正后,结果均变得不显著。此外,对146、152189 和195 等四个同样处于mtDNA 控制区复制起始区域的变异位点的初步 分析,同样没有获得显著的差异。不支持此前在欧洲长寿人群和日本长寿人 群得到的结论。 综上所述,本研究第一次在中国汉族人群中对mtDNA 控制区多态性与 长寿的相关性进行了研究。mtDNA 与人类长寿的关系还有待于更深层次的 机理性研究和功能性研究来揭示。

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精神分裂症是一种复杂的精神疾病,全世界约有1%的人患有这种疾病.以往的研究发现精神分裂症患者的脑容量比正常人小,且一些精神分裂症易感的DNA序列多态性也同时与脑的结构异常有关,这与精神分裂症的神经发育假说是吻合的.最近研究发现人的GULP1基因的两个SNP(rs2004888和rs4522565)与精神分裂症显著相关.为了研究这两个精神分裂症易感的SNP是否也符合神绎发育假说,我们检测了791个正常人的这两个SNP的基因型并测量它们的脑容量,相关性分析发现这两个SNP和脑容量无关,说明GULP1的精神分裂症易感性存在更加复杂的机制.

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The human genome project has been recently complemented by whole-genome assessment sequence of 32 mammals and 24 nonmammalian vertebrate species suitable for comparative genomic analyses. Here we anticipate a precipitous drop in costs and increase in sequ

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本文以中国科学院成都生物研究所培育的同源四倍体水稻和二倍体水稻为材料,进行遗传差异及产量、品质性状的研究:1、以二倍体水稻为对照,研究了同源四倍体水稻在2004 年和2005 年的结实情况。结果同源四倍体的花粉育性、结实率均不同程度下降,尤其低代材料更是大幅度下降。F 检验表明,同源四倍体不同个体间的各产量性状均差异显著,说明其具有很大的遗传改良潜力。从1996 年到2005 年对部分同源四倍体水稻进行了连续选择改良,T 检验表明经过9 年的选择改良,其结实率显著提高。本文还对同源四倍体水稻各产量性状间的相关性进行了分析,结果结实率与花粉育性、穗着粒数、穗实粒数极显著相关;理论产量与花粉育性、有效穗数、穗着粒数、穗实粒数、结实率及千粒重极显著相关。i2、用(CT)n 微卫星标记和PCR-Acc Ι分子标记对40 份同源四倍体和14 份二倍体水稻Wx 基因进行研究。结果,(CT)n 微卫星标记检测,Wx 基因呈Wx1、Wx2 和Wx3 3 种多态性;PCR-Acc Ι 检测,Wx 基因表现为G-型和T-型。测定稻米直链淀粉含量(AC)、胶稠度(GC)和糊化温度(GT),并探讨其与Wx 基因的关系,结果,二倍体和同源四倍体水稻均存在:Wx 基因型相同,AC 差异较小,Wx 基因型不同时,AC 差异较大,Wx1 基因型品种AC 最高, Wx2 基因型品种AC 次之,Wx3 基因型品种AC 最低;基因型相同时,同源四倍体AC 低于二倍体;同源四倍体与对应二倍体间,Wx 基因型相同时,AC 差异很小;而Wx 基因型发生变异时,AC 差异很大。同时,进行相关性分析,结果二倍体和四倍体水稻均存在AC、GC 与Wx 基因密切相关;而GT 与Wx 基因相关不显著。综合分析,(CT)n微卫星标记与PCR-Acc Ι 分子标记检测的相关系数为0.842,呈极显著正相关,可以将其结合起来进行同源四倍体新品种的选育和改良。3、利用RAPD 技术,对同源四倍体和二倍体水稻的遗传差异进行分析。17条引物在同源四倍体中扩增出178 条带(PPB=81.5%),在二倍体中扩增出173条带(PPB=76.3%);同源四倍体和二倍体的Shannon 遗传多样性指数分别为0.4848 和0.4679,多态信息量分别为0.3301 和0.3216,遗传距离分别为0.3572和0.3460;同源四倍体与其对应二倍体间遗传距离为0.1914-0.4633,平均为0.2914。表明同源四倍体的遗传多样性高于二倍体,且同源四倍体与其二倍体之间存在较大的遗传差异,这些将为水稻品种改良和新品种选育提供科学依据。上述产量、品质性状及遗传差异分析的结果,不仅有利于加快同源四倍体水稻的遗传改良进程,而且为进一步研究、利用同源四倍体水稻奠定了初步基础。 AbstractStudy on genetic diversity, yield characters and quality traitsof autotetraploid and diploid riceLiu Yuhua (Botany)Directed by Associate Prof. Tu ShengbinIn this study, diploid and autotetraploid rice, which were cultivated in ChengduInstitute of Biology were analyzed in genetic diversity, yield characters and qualitytraits.In the study, 2 diploid and 29 autotetraploid rice(2n=4x=48) materials, including4 preliminary and 25 advanced generation, were investigated for yield characters.Compared with diploid check, the pollen fertility and seed set of autotetraploiddeclined dramatically, especially in preliminary generation. F-test indicated that therewere remarkable differences among different varieties, showing that autotetraploidmaterials had strong potential for improvement. From 1996 to 2005, someautotetraploid rice had been selected and improved. T-test showed that seed setincreased obviously. The relationships among yield characters of autotetraploid ricewere analyzed. Seed set was strongly correlated with pollen fertility, total grainnumber per panicle and productive grain number per panicle; theoretical yield wasstrongly correlated with pollen fertility, productive panicle number per plant, totalgrain number per panicle, productive grain number, seed set and 1000-grain weight.Wx genotypes of 40 autotetraploid rice and 14 diploid rice were tested by usingthe (CT)n microsatellite marker and a cleaved amplified polymorphic sequence(CAPS) molecular marker named PCR-Acc Ι. Three microsatellite alleles wereproduced, i.e. Wx1, Wx2 and Wx3 both in autotetraploid and in diploid rice.Comparatively, PCR- Acc Ι molecular marker produced two genotypes, G-type andT-type for both autotetraploid and diploid rice. In this study, amylose content (AC), gel of consistency (GC) and gelatinization temperature (GT) of rice grain weremeasured and their relationships with Wx alleles were analyzed. The results showedthat variation of AC between autotetraploid and diploid rice was small when they hadthe same Wx genotype. However, variation of AC turned to be large when the Wxgenotypes were different. Actually, AC met the maximum value in Wx1 varieties andWx2 varieties the middle and Wx3 varieties the minimum. And AC was lower inautotetraploid than in diploid. Correlation analysis was done in this experiment. ACand GC of rice grain were probably controlled by Wx gene or other gene whoselocation was strictly linked to Wx gene, while GT of rice was not. The correlationcoefficient between Wx genotypes which revealed by (CT)n microsatellite marker andPCR-Acc Ι molecular marker was 0.842 with significant level. That revealed aconsistent result between the two types of markers. So it was possible to utilize boththe two types of markers to select and promote germplasm of autotetraploid rice.RAPD molecular markers were used to analyze the genetic diversity betweendiploid and autotetraploid rice. 178 repeatable bands were detected through 17 RAPDprimers with percentage of polymorphic bands was 81.5% in autotetraploid rice while173 repeatable bands were detected with percentage of polymorphic bands was 76.3%in diploid rice. According to the measurement of Shannon index, polymorphicinformation content and genetic distance, genetic diversity of autotetraploid was on ahigher level, genetic variation between autotetraploid and diploid rice was relativelyhigh. All these contributed to the genetic selection and improvement in rice breeding.As mentioned above, the results are not only helpful to promote the process ofrice improvement, but also to confirm the basic for further study of autotetraploid rice.

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Background: Recent studies have proposed that the serine protease inhibitor E2 (SERPINE2) was a novel susceptibility gene for chronic obstructive pulmonary disease (COPD) in Caucasians. However, this issue still remained controversial. Additional evidence

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NYD-SP12 is a recently identified spermatogenesis-related gene with a pivotal role in human testis development. In this study, we analyzed between-species divergence and within-species variation of NYD-SP12 in seven representative primate species, four wo