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关键词： 卵巢衰老   生物学机制   生育能力   绝经期   遗传学   生殖寿命   小鼠动物模型   女性生殖   chek1   绝经前  

摘要： 遗传学研究揭示人类卵巢衰老相关的生物学机制《自然》（Nature）封面：卵巢衰老。《自然》杂志第7872期封面文章报道了与卵巢衰老有关的生物学机制。女性生殖寿命因人而异，时间会影响生育能力和健康情况。自然生育能力从绝经前的5～10年开始下降，而大多数女性的绝经期在40～60岁之间。此研究揭示了这一过程背后的遗传学机制。研究团队分析了20 1323名女性的遗传学数据，识别出290个与绝经时间相关的遗传决定因素；进一步利用小鼠动物模型对基因Chek1、2进行操作，发现能直接影响生育能力和生殖寿命。研究揭示了这一过程背后的遗传学机制，相关结果期望能为延续生育能力、预防疾病提供治疗方法。

摘要： Scincidae is one of the most diverse families of squamates, comprising over 1,300 species of lizards with a variety of life history and ecological traits. This diversity includes three reproductive modes, where some species reproduce via oviparity (egg-laying), viviparity (live birth) or use of a mixed strategy (females switch modes). In this study, it was sought whether reproductive output differs between scincid species using these reproductive modes. Reproductive output is defined as the average product of offspring abundance and size per reproductive event, representing the reproductive effort of an individual. Additionally, the importance of phylogeny (evolutionary relatedness) and a suite of eco-physiological variables in determining reproductive output in scincid mothers were tested. The dataset included 295 scincid species for which these variables were available in the literature. A phylogenetic comparative analysis indicated scincid reproductive output follows similar scaling patterns as other taxonomic groups, with female body size explaining ~86% of the variation in total offspring mass. Size-corrected offspring mass was best explained by a phylogenetic linear model, with most scincid species producing ~21% of maternal body mass per reproductive event. The results share similarities with other animal taxa supporting the possible existence of universal scaling patterns of production rates across animal taxa. These data highlight the importance of formulating a comprehensive phylogenetic comparative analysis of the drivers of reproductive output across animal taxa to determine how natural selection favors the evolution of reproductive strategies that maximize offspring viability and lifetime fitness.

摘要： When an individual interacts socially with a conspecific, their behavioural phenotype is affected directly by their genotype ('direct genetic effect', DGE), but may also be affected indirectly by the genotype of the opposing individual ('indirect genetic effect', IGE). While there is no doubt that IGEs occur in various organisms and contexts, it is unknown how properties of the environment may influence the relative magnitude of DGEs, IGEs, and their covariance. To gain insight into this, I examined territorial interactions in Drosophila melanogaster. Due to their short generation time and relatively simple care requirements, D. melanogaster has been used extensively in quantitative genetic research. Using offspring from a half-sib breeding design, I constructed an arena for documenting multiple dyadic territoriality assays with two sizes of a food resource. With this apparatus, 618 territoriality contests between 1,236 individuals were recorded and scored for four key aggressive behaviours. The results revealed significant genetic variation in how opponent effects on focal individuals changed between environments (i. e., genetic variation in the plasticity of IGEs). In addition, changes in DGEs and IGEs between environments were strongly and positively correlated (i. e., there was a DGE × IGE × environment interaction), although confirmation of this result in further studies is warranted because it was non-significant (P = 0. 10), likely due to large uncertainties arising in part from some small variance component estimates. As a high throughput system for quantify IGEs in territoriality in Drosophila, my approach holds promise but there are issues to resolve, including automating phenotyping behaviors in place of manual scoring to enable many more trials. Additionally, modifications to increase humidity during trials might result in increased expression of certain territorial behaviours.

关键词： 医学遗传学  

ISBN: (纸本)9787117331289

摘要： 本书分3篇共14章：第一篇，遗传的物质基础，包括遗传的细胞基础、遗传的分子基础和表观遗传学。第二篇，人类遗传病，包括单基因遗传病、多基因遗传病、线粒体遗传病、染色体病、遗传病的诊断与治疗、遗传病的预防与优生。第三篇，医学遗传学专题，包括群体遗传学、免疫遗传学、肿瘤遗传学、药物遗传学。

摘要： Glomerulonephritis comprises a heterogenous group of diseases that represent a common cause of impaired kidney function. Many are immune-mediated with antibodies directed against various self-antigens that form immune complexes and activate complement through the classical, alternative or lectin-binding pathways. Complement deposits are found in IgA, membranous and lupus nephropathy, anti-GBM disease, Focal and Segmental Glomerulosclerosis (FSGS) and fibrillary glomerulonephritis, and often correlate with more severe disease and a worse prognosis. The evidence for complement activation in glomerulonephritis includes glomerular complement deposits, low plasma complement levels in active disease, milder disease where complement is absent from the deposits, mild disease in animal models where serum complement levels are depleted, and the association with genetic complement variants in different forms of glomerular disease. There are also case series and reports of retinal drusen in C3 glomerulopathy, systemic lupus erythematosus, IgA and some other forms of glomerulonephritis. Retinal drusen are white-yellow deposits of oxidised lipids, immunoglobulins, complement and amyloid in Bruch's membrane that are characteristic of age-related macular degeneration. The pathogenesis of drusen is well described with 37 genetic loci that affect multiple pathways including the complement system. Drusen have a similar composition to the glomerular immune deposits and their occurrence in glomerulonephritis is further evidence for complement activation in these conditions but also suggests that drusen represent a model for glomerular immune deposition and a biomarker for disease activity. Hence, studying drusen in glomerulonephritis may help identify further shared pathways in the pathogenesis of glomerular disease. The pathogenesis of immune-mediated glomerulonephritis is incompletely understood and treatment is still not optimal. Complement activation may represent a common mechanism

关键词： 先天性心脏病   基因变异   剪接位点变异   Minigene技术  

摘要： 背景 先天性心脏病（Congenital heart disease,CHD）是一类由胚胎期心血管发育异常导致的心脏及大血管结构功能缺陷疾病,居婴幼儿出生缺陷首位,活产儿发病率为10‰～12‰。CHD依据生理解剖学可划分为间隔缺损、梗阻性缺陷及复杂性心血管畸形,依据有无合并其它缺陷可分为综合征型CHD和单纯型CHD。CHD病情严重者可降低生活质量甚至导致死亡。因此,积极寻找病因并预防下一代缺陷是如今针对CHD的有效手段。除环境因素以外,遗传因素在CHD病因中占据重要角色,包括染色体异常、拷贝数变异及基因变异。基因变异又细分为小的插入、缺失和单核苷酸变异。目前研究已发现至少50余种CHD相关基因,但由于CHD临床表型多有交叉,不同家庭可能存在不同遗传背景,CHD的致病基因鉴定尚不完全明确,仍有相当部分的CHD相关基因及其变异有待深入研究。 目的 本研究采用全外显子组测序技术（Whole Exome Sequencing,WES）对5个排除染色体及CNV异常的CHD家系进行致病基因变异分析,明确其遗传背景,帮助判断再发风险,为这类家系遗传咨询及产前诊断提供指导依据。同时针对其中1个家系所发现的TBX5基因c.663+1G>C新剪接位点变异进行体外功能鉴定,探究变异引起异常剪接的机制,综合评价该变异的致病性。 方法 （1）采集患者病史及家族史,绘制家系图,提取家系部分人员血液基因组DNA,采用WES技术进行致病基因筛选,结合疾病相关数据库（ClinVar,HGMD）及多种生物信息学软件（SIFT、Polyphen2、Mutation Taster、VarSite）进行分析,使用ACMG指南综合评价候选基因变异致病性。 （2）采用Minigene技术进行实验,选取pEX-3作为质粒载体,将新剪接位点变异所在内含子及其前后2个外显子作为目的基因,分别构建野生型及突变型重组质粒,转染至HEK293T细胞,提取RNA并反转录,琼脂糖电泳得到cDNA条带,最后对cDNA条带进行测序,以此鉴定目的基因表达的mRNA产物差异,来分析体外正常和变异基因的剪接能力。 结果 （1）CHD-01 家系检测到FBN1基因（NM000138）c.2113G>A杂合变异,CHD-02家系检测到FBN1基因（NM000138）c.6772T>C变异,均为明确的致病变异,可导致常染色体显性遗传的Marfan综合征。 （2）CHD-03 家系检测到FGF13 基因（NM004114）c.227G>A变异,经ACMG指南评为意义不明变异,变异可导致X染色体显性/隐性遗传的发育性癫痫性脑病90型;CHD4基因（NM001273）c.2249C>T变异经ACMG指南评为致病变异,变异可导致染色体显性遗传的Sifrim-Hitz-Weiss综合征。 （3）CHD-04 家系检测到GDF1基因（NM001492）c.10471050delCTTT及c.478G>T复合杂合变异,ACMG指南均评为意义不明变异,可导致常染色体隐性遗传的右心房异构疾病及常染色体显性遗传的多型先天性心脏病。 （4）CHD-05 家系检测到TBX5 基因（NM000192）c.663+1G>C变异,ACMG指南评为致病变异,变异可导致常染色体显性遗传的Holt-Oram综合征。 （5）针对CHD-05家系TBX5基因c.663+1G>C新剪接位点变异进行Mingene技术实验,结果表明野生型目的基因正常转录剪接去内含子,得到成熟mRNA,而突变型目的基因缺失了相应的条带,说明c.663+1G>C变异的存在使mRNA前体在剪接内含子时出现错误,无法正常转录出成熟mRNA。 结论 （1）CHD-01家系及CHD-02家系诊断为FBN1基因变异导致的Marfan综合征;CHD-03家系为CHD4基因变异导致的Sifrim-Hitz-Weiss综合征;CHD-04家系为GDF1基因变异导致的右心房异构疾病;CHD-05家系为TBX5基因变异导致的Holt-Oram综合征。 （2）检出的2个明确的致病变异及5个可疑致病变异丰富了CHD的致病基因变异谱,为这类存在CHD临床表型的家系遗传咨询及产前诊断提供了指导思路,为再发风险判断提供了重要依据。 （3）Mingene技术在转录水平鉴定出TBX5基因c.663+1G>C新剪接位点变异导致异常剪接,使基因无法正常转录,进而可能影响转录因子TBX5蛋白的结构和功能。实验丰富了对TBX5基因c.663+1G>C的致病性研究,为该变异导致CHD-05家系罹患Holt-Oram综合征提供了实验依据。

关键词： 心房心肌病   心肌肥大   表观遗传学   转录调控   血管紧张素Ⅱ  

摘要： 研究背景: 心房疾病的定义经历了从“心房颤动”、“心房心肌病”到“心房衰竭”。2016年欧洲心律协会通过专家共识正式提出心房心肌病的定义,根据心房心肌病的组织病理学特征,专家共识将心房心肌病分类为四个亚型,其Ⅰ型和Ⅲ型的主要病理特征是心房肌肥厚(心房肌细胞肥大)。心房肌与心室肌肥厚具备相似的发病机制,近年来不断有研究证实表观遗传学调控在心室肌肥厚中发挥重要作用,而心房肌肥厚,作为心房心肌病的重要病理学特征之一,表观遗传学机制是否亦在其发生发展中发挥作用?本研究旨在探讨心房心肌病心肌细胞肥大的表观遗传学机制。 研究内容与方法: 心外科手术中收集8例慢性持续性房颤和7例窦性心律患者的右心房心耳组织样本,酶联免疫吸附试验检测心房组织中血管紧张素Ⅱ含量,western-bloting检测心房肌肥大相关基因:心房利钠肽、脑利钠肽蛋白表达,染色质免疫共沉淀检测肥大相关基因启动子序列富集心肌细胞增强因子2、组蛋白去乙酰化酶、组蛋白H3K27、H4乙酰化水平。新生大鼠心房肌细胞原代培养,血管紧张素Ⅱ诱导心房肌细胞肥大,血管紧张素Ⅱ受体拮抗剂氯沙坦拮抗AngⅡ作用,westernbloting检测心房肌肥大基因蛋白表达,染色质免疫共沉淀检测肥大相关基因启动子序列MEF-2、HDAC、组蛋白H3K27、H4乙酰化富集水平。RNA测序(RNAseq)分析基因转录组。 研究结果: 与窦性心律组患者相比,房颤患者心房明显增大,表现为房性肥厚和房性心肌病。与窦性心律组患者相比,房颤组患者心房肌组织中血管紧张素Ⅱ水平、肥大相关基因蛋白表达、肥大基因启动子序列富集的心肌细胞增强因子2、组蛋白H4、H3K27乙酰化丰度较窦性心律患者升高,但肥大相关基因启动子序列富集组蛋白去乙酰化酶减少。在原代心房肌细胞培养实验中,血管紧张素Ⅱ体外培养增加了原代心房心肌细胞的横截面面积,诱导了肥大相关基因蛋白表达增加,促进组蛋白去乙酰化酶-4和-5的磷酸化,并诱导了二者的出核转运。染色质免疫共沉淀结果同时提示:血管紧张素Ⅱ诱导的心肌肥大基因启动子序列富集心肌细胞增强因子-2,染色质组蛋白H4、H3K27乙酰化修饰丰度的增加与在启动子上的富集的组蛋白去乙酰化酶丰度降低有关。RNA测序分析提示血管紧张素Ⅱ能够显著上调心肌能量与结构重构基因的表达。上述血管紧张素Ⅱ诱导的促肥大细胞效应均可被血管紧张素Ⅱ受体拮抗剂氯沙坦,Ca MK(Ca(2+)/钙调蛋白依赖性激酶)抑制剂KN93和蛋白激酶D抑制剂CID755673治疗部分逆转。RNA测序分析显示,AngⅡ显著上调与心肌能量重构与结构重构相关的基因转录组转录。 结论: 房颤患者对心房肌肥大的神经内分泌易感性增加,肥大相关基因转录激活的表观遗传学特质增加。心肌细胞增强因子-2可能作为平台,通过交换组蛋白乙酰转移酶和去乙酰化酶实现对正或负向转录信号作出应答。血管紧张素Ⅱ诱导的去乙酰化酶出核转运及由此引发的组蛋白乙酰化修饰增加可能是一种新的心房肥大调节机制,可能作为心房心肌病治疗的新策略。血管紧张素Ⅱ对心房心肌病有促肥厚作用,成部分表观遗传学依赖。因此,可以探索表观遗传干预治疗房性心肌病等心房相关临床疾病。

摘要： Despite breakthroughs made by genome-wide association studies (GWAS) in our understanding of psychosis, further research is still needed to characterise the effects of the genetic variants identified and clarify the neurobiological mechanisms underlying these associations. In this thesis, I aim to bridge these knowledge gaps by studying endophenotypes for psychosis, which are intermediate phenotypes associated with the genetics of psychosis that pinpoint abnormalities in a specific neurobiological domain. In Chapter 1, I conducted a meta-analysis on the N100 event-related potential, combining the results of a local family study and previous literature. I found reduced N100 amplitudes and prolonged N100 latencies in both patients with psychosis and their unaffected relatives compared to controls, suggesting that the N100 is a promising endophenotype. Further analysis of the local family study revealed that the N100 was associated with the CHRNA4 gene, indicating the potential involvement of nicotinic acetylcholine receptors in the N100. In Chapter 2, I computed gene-set specific polygenic risk scores for psychosis by stratifying polygenic risk scores into specific biological domains and tested their associations with established endophenotypes. I found that reduced P300 amplitudes were associated with abnormalities in early brain development in psychosis, supporting the neurodevelopmental hypothesis of schizophrenia. Finally, Chapter 3 involves a mixed-model GWAS on adolescent verbal memory as a psychosis endophenotype in a sample of diverse genetic ancestry. I found new evidence of a significant genetic correlation between schizophrenia and verbal memory in adolescents, consistent with previous observations in family studies. Furthermore, I discovered two genome-wide significant loci that influence verbal memory performance. In particular, the NSF gene identified by my GWAS is involved in synaptic neurotransmission and membrane fusion, and thus my data suggest it pl

关键词： 猪   短串联重复序列   群体遗传学   肝脏组织   基因表达   候选因果变异  

摘要： 猪是重要的农业动物之一,猪肉约占世界肉类消费总量的40%。野猪起源于东南亚地区,在亚洲和欧洲两个中心被独立驯化成家猪;并不断向世界各地扩散,形成丰富多样的家猪品种。对猪基因组的遗传学研究,不仅有利于剖析猪的群体结构、遗传多样性、驯化和进化,也有利于解析猪复杂性状的因果机制、提高育种效率和生产性能。然而,前人的研究主要集中在猪基因组中SNP、INDEL、CNV和SV等变异的功能,而忽视了短串联重复序列变异(STR)的重要作用。STR,又称简单重复序列(SSR),是指基因组上核心基序长度为1-6碱基的串联重复DNA序列。STR约占真核生物基因组总长的0.5%-15.5%,具有高度多态性;STR曾经被认为是没有功能的“垃圾DNA”,但最近多项研究表明,STR在动植物基因表达和复杂性状的调控中发挥着重要作用。本研究收集来自全球22个家猪品种、2个野猪群体和7个其他猪属共计394个样本的全基因组重测序数据,利用TRF和lob STR软件,共鉴定到878967个多态性STR变异(p STR),大幅扩充了猪STR变异数据库。研究发现:(1)编码区域的p STR受到了纯化选择的影响;CCG、AGG和AGC等三核苷酸p STR在CDS、5'UTR和H3K4me3区富集,而ACAGCC重复序列在SINEs元件中显著富集,表明这些STRs在猪基因组中具有重要的功能。(2)利用近三十万个高质量的p STR对品种的分类效果要好于全基因组SNP数据。(3)鉴定了14125个拷贝数扩张评分大于10的p STR,其中位于A3AGLT2基因的p STR在亚欧猪群间分化极其显著。(4)在亚洲野猪和家猪之间,鉴定了1484个显著分化的p STR,最显著信号位于TBX19、MSTN、SFT2D2和AHR等基因附近;在欧洲野猪和家猪之间,共鉴定了1325个显著分化的p STR,最显著信号位于MFSD12、NR6A1、FAF1和LAS1L等基因附近。(5)在中国地方猪环境适应性分析中,共有3268个p STR与年平均温度变异显著关联,涉及EDA、METTL8和FAM155B等基因;共有2692个p STR与高原适应性显著关联,涉及EPAS1、PDK1和PIK3C2B等基因。在分析家猪与野猪之间的分化以及中国地方猪环境适应性时,我们还发现许多p STRs比SNPs的信号更显著,支持了STR在鉴别选择信号等群体遗传学领域可以提供重要的补充信息。总之,本研究提供了迄今为止最全面的猪基因组p STR集合,并阐明了短串联重复序列变异在猪进化、驯化和环境适应中的作用。为了探究STR变异对基因表达的影响,本项目专门研究了家猪嵌合家系F6和F7世代全基因组重测序及其对应的肝脏组织全基因组表达谱数据。其中,F6和F7群体的样本量大小在质控之后分别为260和296。在F6和F7世代的肝脏组织中,分别鉴定出5,203和5,868个与基因表达显著相关的STRs(e STRs,FDR<1%)。正交验证分析表明,不同群体间显著性e STR的重复率为92%。与e SNP比较发现,e STR的遗传力约为顺式遗传力的1/4;利用贝叶斯精细定位法,在F6和F7中分别确定了235和298个候选的FMe STR(Fine-Mapped e STR),且两个群体间共享12个e Genes,分别是ABTB1、ASB5、NDUSF5、CARD19、MPG、KNJ18、RTTN、IL33、BCKDK、RAB4B、SNX33和ARPC5基因。此外,我们发现FMe STR在猪基因组中内含子区域,以及ATAC、HIC Compartment A和H3K4me3等表观遗传修饰区域显著富集。最后,我们观察到数百个e STRs与GWAS SNPs有共定位,其中20个位于GWAS-SNP附近的FMe STR又与表观遗传修饰峰重叠,其靶基因的功能与GWAS表型相关,提示这些STR很可能是候选的因果变异。例如,第9号染色体上的一个FMe STR落在H3K4me3、H3K27ac和ATAC的保守峰上,又与血细胞计数的GWAS SNP毗邻,且显著影响了CLPB基因的表达。综上所述,本研究对猪肝组织的e STRs进行了全面的调查,证实了STR变异对猪肝脏组织的基因表达具有显著的调控作用,为研究复杂性状的遗传基础提供了重要的见解。