中国山杨遗传多样性及遗传结构分析

利用6个单拷贝核基因标记,对中国山杨(Populus davidiana Dode)14个自然居群的遗传多样性和遗传分化水平进行了研究。结果表明,中国山杨表现出较高的遗传多样性水平,各居群间基因流(Nm)为0.66;居群内的变异占总变异的百分比(71.82%)大于居群间(28.18%)。Mantel test检验结果显示居群遗传距离和地理距离间没有相关性。失配分布检测显示中国山杨历史上曾经历过种群的扩张。复杂的种群历史动态、高度异交和较高的碱基突变速率是中国山杨遗传多样性水平较高的原因;而较强的花粉和种子扩散能力及中国山杨的连续分布可能是其居群间遗传分化较小的原因。     

中国重要海洋动物遗传多样性的研究进展

海洋动物遗传多样性的研究不仅可以揭示物种的起源与进化历史,而且为遗传资源的保存、海水养殖动物育种和遗传改良及整个海洋生态环境的修复和稳定等工作提供理论依据.本文概述了近十几年来我国重要海洋动物(主要包括鱼类、虾蟹类和贝类)遗传多样性研究所取得的成果,具体阐述其在种质鉴定、系统进化、群体遗传结构分析和良种培育等方面的应用,以期进一步推动海洋动物遗传多样性研究,加快优良种质的培育,促进海水养殖业的健康发展,实现海洋生物资源的合理开发和可持续利用.     

牦牛分子遗传多样性研究进展

遗传多样性研究可有效地揭示牦牛的遗传变异, 是牦牛群体遗传学研究的主要内容之一。自20世纪70年代以来, 人们已对牦牛的体形外貌特征、染色体核型(带型)、生理生化特性和DNA序列变异等进行了较为深入地研究。随着分子遗传学和DNA测序技术的迅猛发展, 近年来的研究主要集中在牦牛的分子遗传多样性。文章对近15年来牦牛mtDNA和核基因组分子标记及侯选基因多样性的研究现状进行了综述, 对前景进行展望, 以期为牦牛群体基因组学等研究提供依据。     

人类线粒体的遗传

阐明了人类线粒体基因组特殊的分子结构和遗传学特征,论述了人类线粒体病独特的遗传方式。     

人类基因组单核苷酸多态性的研究进展

随着分子遗传学的进展 ,疾病遗传学研究从简单的单基因疾病转向复杂的多基因疾病 (如骨质疏松症、糖尿病、心血管疾病、精神性紊乱、各种肿瘤等 )与药物基因组学的研究。与前者相比 ,多基因性状或遗传病的形成 ,受许多对微效加性基因作用。这些不同基因构成的遗传背景中 ,可能有易感性主基因 (ｍａｊｏｒｇｅｎｅ)起着重要作用。它们同时还受环境因素的制约 ,彼此间相互作用错综复杂 ,所以任一基因的多态性对疾病发生仅起微弱的作用。鉴于此 ,需要在人类基因组中找到一种数目多、分布广泛且相对稳定的遗传标记。单核苷酸多态性 (ｓｉｎｇｌ…     

水稻SSR标记的遗传多样性研究进展

本文从SSR标记优点和适用于研究水稻遗传多样性入手,综述了SSR标记在水稻核心种质构建与评价、遗传结构、稻种起源演化等方面的研究进展。总结了水稻遗传多样性的地带性特征（云南是中国稻种资源的最大遗传多样性中心和优异种质的富集地;西南稻区粳稻品种遗传多样性最丰富;南方稻区粳稻品种的遗传多样性高于北方粳稻遗传多样性）、遗传多样性与生态地理位置密切相关、目前水稻品种遗传基础狭窄、多样性降低等特征,分析了遗传多样性成因及影响因素,特别指出了育种行为对遗传多样性的影响,并针对当前水稻品种遗传多样性较低的问题提出了对策。     

中国龙虾微卫星标记的筛选及遗传多样性分析

文章以M13通用引物和重复序列(CT)₁₅、(AT)₁₅引物, 利用PCR法对中国龙虾(Panulirus stimpsoni Hoehuis)部分基因组DNA文库进行筛选。共获得78个微卫星序列, 分别分布于55个阳性重组克隆中, 其中完美型(perfect)共50个, 占64%; 非完美型(imperfect)3个, 占3.8%; 混合完美型(compound perfect)6个, 占7.7%; 混合非完美型(compound imperfect)19个, 占24.5%。根据微卫星序列, 设计并筛选出15对微卫星多态性引物, 对中国龙虾的群体进行了遗传多样性分析。获得3~12个等位基因, 等位基因大小在78~425 bp之间, 基本符合引物设计的理论长度。期望杂合度范围为0.48~0.87, 平均值为0.71, 表明中国龙虾基因组微卫星具有较高的杂合度与遗传多样性。15个微卫星位点的PIC值从0.44到0.84, 平均值为0.60, 说明这些微卫星位点在中国龙虾基因组中包含丰富的遗传信息, 合适用于中国龙虾的各种分子标记及遗传学分析和应用。     

人类血型系统与遗传标记

提到血型,人们自然会想到ABO血型系统。目前就红细胞抗原来讲,已经发现的血型系统有20多个。本文拟就人类常见的血型系统及其做为遗传标记的应用简介如下。 (一)人类的血型系统虽然人的所有血液成份的遗传有多态性,包括组织适应性白细胞抗原(Histocompatibility Leucocyte Antigen,HLA)系统,统称为血型。但是血型这一术语习惯上只限于红细胞。     

应用微卫星标记进行大豆种质多样性和遗传变异性分析

微卫星标记又称ＳＳＲ标记是近年来发展的一种新型的分子标记可有效地进行基因型鉴定,系统谱分析并可估算材料间的遗传距离。用５对ＳＳＲ引物对１５份大豆材料进行扩增,共得到２１条多态性条带。每个ＳＳＲ座位的等侠基因数目为３～＾个,基因多样性范围为０．４３７～０．６６８,对这些材料进行了遗传距离分析。家系分析表明微卫星ＤＮＡ经过多世代的九分裂的后产生了突变,在ＲＩＬ Ｆ８代中有的个体在个别ＳＳＲ等基因的大小     

新冠肺炎遗传易感基因的研究进展

新型冠状病毒(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)感染人体后,个体间存在显著不同的新冠肺炎(corona virus disease 2019,COVID-19)临床症状。机体遗传因素在新冠病毒感染后的临床转归过程中发挥重要的作用。以全基因组关联研究(genome-wide association studies, GWAS)为代表的遗传关联研究方法,已成功鉴定了多个与新冠肺炎相关的易感基因,为新冠肺炎防诊治措施的研发提供了理论基础。本文综述了新冠肺炎遗传易感基因的研究进展,包括多种表型、多个人群、多种遗传变异类型的新冠肺炎全基因组关联研究以及易感基因区域的精细定位研究等,旨在为新冠肺炎遗传易感基因的后续研究提供参考。     

人源札幌病毒抗原多样性及遗传进化研究进展

人源札幌病毒(human sapovirus, HuSaV)是全球范围内引起散发性急性胃肠炎和相关疫情的重要病原,尤其对婴幼儿及免疫缺陷患者等高危人群存有致死的危险,人源札幌病毒具有丰富的抗原和遗传多样性,其抗原多样性及免疫原性主要位于P2亚结构域,并且衣壳蛋白免疫原性是人源札幌病毒疫苗研发的理论基础。由于人源札幌病毒可以耐受高衣壳突变而不失去病毒功能使它得以迅速进化,其在宿主体内进化过程中存在连续的氨基酸突变,且突变主要在VP1的P结构域内积累,少见于非结构蛋白和VP2中。序列和结构的改变使得人源札幌病毒逃脱先前存在的群体免疫,有必要进一步探索人源札幌病毒的免疫逃逸机制及其拮抗宿主的免疫应答。因此,本文针对人源札幌病毒在基因组特征、抗原多样性特点、遗传进化机制等领域的研究进展进行了系统综述,并对未来研究中亟待解决的科学问题进行了展望。     

The conservation utility of mitochondrial genetic diversity in macrogenetic research

Conservation Genetics -     

The genetic diversity of cultivated soybean grown in China

Cultivated soybean (Glycine max) is an economically important crop that is grown for its oil and protein products. A better knowledge of its genetic diversity will be valuable for the utilization, conservation, and management of germplasm collections. Using the database of the National Germplasm Evaluation Program of China (NGEPC), we studied the geographical distribution of accessions, the genetic diversity of 15 qualitative and quantitative characters, and the genetic diversity centers of cultivated soybean in China using variation in these 15 traits and genetic diversity indexes (Shannon index). Cultivated soybean is widely distributed throughout China. As an indication of its distribution, a line can be roughly drawn from the Daxinganling mountains in northeastern China to the Qingzang plateaus in southwestern China based on the abundance of accessions and locations of the collections. Of the 22,637 known accessions in China, the 20,570 collected over a vast area between latitudes 18° and 53°N and longitudes 80° and 136°E were used in this study. The Shannon indexes of various morphological traits were calculated. Cultivated soybean accessions were found to exhibit a higher genetic diversity in the area between 34°–41°N and 110°–115°E. On the basis of the geographical distribution of a number of accessions, and their genetic diversity, one genetic diversity center—downstream of the Yellow River Valley—is proposed. Based on these results and on Vavilovs theory on crop origins, one possible diversity center was proposed.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00122-003-1503-xCommunicated by C. Möllers     

口腔微生物多样性研究进展

口腔微生物多样性的改变是口腔常见感染性疾病的发病机制之一,随着分子生物学技术的普遍应用,研究者能够不通过纯培养技术即可对人类口腔不同生态系的微生物组成及变化进行研究。本文综述了当前口腔微生物多样性研究的常用方法及各自的特点,从而为口腔微生物生态方面的进一步深入研究提供参考。     

The influence of recombination on human genetic diversity

In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution.     

The role of cytochemistry in human genetic research

The role of cytochemistry in human genetics is reviewed. In basic research, autoradiography and cytochemical staining procedures for DNA, RNA, proteins and other cell constituents have contributed to the understanding of the way DNA is localized, duplicated and translated. The development of new "banding techniques" for the identification of human chromosomes and parts of these together with somatic cell hybridization procedures have significantly contributed to the mapping of the human genome. Cytochemical methods have also been of great help in the elucidation of the responsible molecular defects in Mendelian disorders based on a single gene mutation. The combination of immunological methods and electron-microscopical cytochemistry now enables different posttranslational processing defects to be related to various subcellular compartments. Cytochemistry is also likely to be of importance for the direct demonstration of gene mutations using recombinant DNA technology. Examples are given of contributions of cytochemical methods to the early diagnosis and prevention of congenital disorders. The main examples are the early diagnosis of patients with a chromosomal aberration and of carriers with a balanced translocation. Early genetic counseling of couples at risk forms the basis for prevention of subsequent affected children. Cytochemistry also contributes to the early detection of heterozygotes of X-linked mutations. Finally, autoradiography and ultramicrochemical procedures have been of great help in improving the prenatal diagnosis of genetic metabolic diseases.     

The genetic diversity of annual wild soybeans grown in China

Annual wild soybeans (Glycine soja), the ancestors of cultivated soybeans (G. max), are important sources of major genes for resistance to pests, diseases and environmental stresses. The study of their genetic diversity is invaluable for efficient utilization, conservation and management of germplasm collections. In this paper, the number of accessions, the variation of traits, the genetic diversity indexes (Shannon index) and the coefficient of variation were employed to study the geographical distribution of accessions, genetic diversity of characters and genetic diversity centers of annual wild soybean by statistical analysis of the database from the National Germplasm Evaluation Program of China. Most annual wild soybeans are distributed in Northeast China, and the number of accessions decreases from the Northeast to other directions in China. The genetic diversity indexes (Shannon index) were 0.49, 0.74, 0.02, 0.55, 1.45, 2.41, 1.27 and 1.89 for flower color, sootiness of seed coat, cotyledon color, pubescence color, hilum color, leaf shape, stem type and seed color, respectively. Coefficients of variation were 7.1%, 28.7%, 76.43% and 18.2% for protein content, oil content, 100-seed weight and days to maturity, respectively. Three genetic diversity centers, the Northeast, the Yellow River Valley and the Southeast Coasts of China, are proposed based on the geographical distribution of the number of accessions, genetic diversity and the multivariate variation coefficient. Based on these results and Vavilov’s theory of crop origination, two opposing possible models for the formation of the three centers are proposed, either these centers are independent of each other and the annual wild soybeans in these centers originated separately, or the Northeast center was the primary center for annual wild soybeans in China, while the Yellow River Valley center was derived from this primary center and served as the origin for the Southeast Coast center. Received: 25 June 2000 / Accepted: 18 October 2000     

The role of cytochemistry in human genetic research

Summary The role of cytochemistry in human genetics is reviewed. In basic research, autoradiography and cytochemical staining procedures for DNA, RNA, proteins and other cell constituants have contributed to the understanding of the way DNA is localized, duplicated and translated. The development of new banding techniques for the identification of human chromosomes and parts of these together with somatic cell hybridization procedures have significantly contributed to the mapping of the human genome.Cytochemical methods have also been of great help in the elucidation of the responsible molecular defects in Mendelian disorders based on a single gene mutation. The combination of immunological methods and electron-microscopical cytochemistry now enables different posttranslational processing defects to be related to various subcellular compartments. Cytochemistry is also likely to be of importance for the direct demonstration of gene mutations using recombinant DNA technology.Examples are given of contributions of cytochemical methods to the early diagnosis and prevention of congenital disorders. The main examples are the early diagnosis of patients with a chromosomal aberration and of carriers with a balanced translocation. Early genetic counseling of couples at risk forms the basis for prevention of subsequent affected children. Cytochemistry also contributes to the early detection of heterozygotes of X-linked mutations. Finally, autoradiography and ultramicrochemical procedures have been of great help in improving the prenatal diagnosis of genetic metabolic diseases.In honour of Prof. P. van Duijn     

苔藓植物遗传多样性研究现状

苔藓植物具有丰富的遗传多样性 ,本文分别从形态学、细胞学、生化水平和分子水平阐述其遗传多样性的研究现状。     

The impact of recent events on human genetic diversity

The historical record tells us stories of migrations, population expansions and colonization events in the last few thousand years, but what was their demographic impact? Genetics can throw light on this issue, and has mostly done so through the maternally inherited mitochondrial DNA (mtDNA) and the male-specific Y chromosome. However, there are a number of problems, including marker ascertainment bias, possible influences of natural selection, and the obscuring layers of the palimpsest of historical and prehistorical events. Y-chromosomal lineages are particularly affected by genetic drift, which can be accentuated by recent social selection. A diversity of approaches to expansions in Europe is yielding insights into the histories of Phoenicians, Roma, Anglo-Saxons and Vikings, and new methods for producing and analysing genome-wide data hold much promise. The field would benefit from more consensus on appropriate methods, and better communication between geneticists and experts in other disciplines, such as history, archaeology and linguistics.