Genetic variation in human erythrocyte acetylcholinesterase

A method for solubilization of human erythrocyte membranes was developed and used to survey 70 unselected human blood samples for isozymic variation of stromal acetylcholinesterase. Three variants were observed. Pedigrees of families studied by this method indicated that this variation represented the phenotypic expression of two codominant alleles at a single locus.     

猪LPL基因PCR-RFLP遗传变异的研究

利用PCR-RFLP技术,对大白猪、长白猪、杜洛克、荣昌猪、内江猪、八眉猪、汉中白猪、汉江黑猪8个家猪品种和1个野猪种共368头猪LPL基因的第6和第8内含子进行遗传变异研究。结果表明:(1)在第6内含子的Sma -RFLP位点上,各猪种均存在多态性,长白、杜洛克、内江猪和八眉猪以AA和AB基因型为主,大白、荣昌猪、汉中白猪、汉江黑猪及野猪以AB和BB基因型为主;在Pvu -RFLP位点上,国外猪种均为DD纯合子,而国内猪种和野猪在此位点上均存在变异;(2)在第8内含子的Hind -RFLP位点上,国外猪种和荣昌猪表现出多态性,而国内其他猪种和野猪均为FF纯合子;在EcoR -RFLP位点上,各猪种均表现多态性,且以GH杂合子为主,没有表现出差异。     

辽宁绒山羊抑制素A基因遗传变异与双羔性状的关联分析

以抑制素A基因(Inhibin alpha subunit gene,INHA)作为辽宁绒山羊双羔性状的候选基因,以便为绒山羊育种工作中分子标记选择提供理论依据。运用测序法寻找辽宁绒山羊INHA基因单核苷酸多态性,筛查到一个新的多态位点-446TC,该位点位于INHA基因的启动子区域。运用PCR-RFLP法验证并分析该位点在辽宁绒山羊双羔群体和单羔群体间的多态性。结果表明,在辽宁绒山羊中双羔和单羔群体中分布A、B两个等位基因,处于中度多态。经χ2检验,样本在该位点未达到Hardy-Weinberg平衡状态(P0.05),不同基因型在辽宁绒山羊单、双胎群体上差异达到显著水平(P0.05)。     

蒙古冰草种质资源的遗传变异

对内蒙古中东部地区6个天然居群及内蒙沙芦草和蒙古冰草新品系2个栽培品种(系)的遗传多样性研究结果进行了综合评价,发现蒙古冰草具有极为丰富的遗传多样性,且居群内的遗传变异大于居群间,同时天然居群的遗传多样性也明显高于栽培品种(系);另外,两个栽培品种(系)间也存在有相当程度的遗传分化,表明了人工选择在其中所起到的重要作用;UPGMA聚类分析的结果显示,蒙古冰草的8个居群基本上可被分为与其生境土壤条件和生长条件相适应的3个类群,即沙地居群,石砾质坡地居群和沙壤质土栽培品种(系)3类,充分反映天然环境条件和人为环境条件或者说自然选择和人工选择对蒙古冰草居群间遗传分化的巨大影响.     

小麦根系PIP2基因表达响应干旱复水的遗传差异研究

【目的】研究干旱-复水的水分动态变化及品种遗传特性对小麦水孔蛋白基因PIP2表达的影响,揭示小麦生理抗旱性的分子机制。【方法】以抗旱性差异较大的2个小麦品种"陕合6号"(抗旱)和"郑引1号"(干旱敏感)为材料,于幼苗培养至8d时,采用渗透势为-0.4MPa的PEG-8000溶液模拟干旱胁迫处理,胁迫时间分别为0(对照),12,36,60h,胁迫60h后复水36h。运用半定量RT-PCR方法,研究从干旱胁迫到复水的整个过程中,水孔蛋白基因PIP2在2种小麦根系中的动态差异表达情况,以及根系水导、叶片相对含水量、游离脯氨酸含量和细胞膜相对透性的变化。【结果】正常水分条件下,"郑引1号"中PIP2的表达水平高于"陕合6号";而水分胁迫条件下,"陕合6号"中PIP2的表达量普遍高于"郑引1号",且PIP2的表达随水分的动态变化在2个品种中均表现出明显的可塑性。水分胁迫初期(36h内),"陕合6号"中PIP2的表达水平显著高于对照,至60h时又逐渐降低至低于对照水平;而"郑引1号"PIP2的表达量随着水分胁迫时间延长持续降低,至60h时几乎检测不到其表达。胁迫60h后复水36h,2个小麦品种中PIP2的表达量均有恢复,但"郑引1号"的净表达量仍未达到胁迫前的水平,而"陕合6号"则超过了胁迫前的水平,表现出补偿效应。与干旱敏感品种"郑引1号"相比,干旱胁迫下抗旱品种"陕合6号"的高PIP2转录水平对应于植株较高的根系水导、叶片相对含水量和游离脯氨酸含量,同时具有较低的根系细胞膜相对透性。【结论】抗旱品种在水分胁迫初期诱导并维持较高的PIP2表达,复水后PIP2的补偿表达可能是其具有较高抗旱能力的重要机制之一。     

Cis-acting regulatory variation in the human genome

The systematic screening of the human genome for genetic variants that affect gene regulation should advance our fundamental understanding of phenotypic diversity and lead to the identification of alleles that modify disease risk. There are several challenges in localizing regulatory polymorphisms, including the wide spectrum of cis-acting regulatory mechanisms, the inconsistent effects of regulatory variants in different tissues, and the difficulty in isolating the causal variants that are in linkage disequilibrium with many other variants. We discuss the current state of knowledge and technologies used for mapping and characterizing genetic variation controlling human gene expression.     

2014—2016 年广东省PRRSV GP5 基因遗传变异分析

为监测猪繁殖与呼吸综合征病毒(PRRSV)的遗传变异情况,采集了2014—2016年间广东地区46个猪场317份疑患PRRS的临床样品进行检测,并对阳性样品的GP5基因进行了RT-PCR扩增、克隆和测序,选出21株PRRSV GP5基因进行序列比对和遗传进化分析。结果表明:所分离的PRRSV均属于美洲株,21株PRRSV GP5基因的核苷酸和氨基酸同源性分别为82.4%~98.7%和78.6%~98.5%,其中2株与美国NADC30分离株同属亚群Ⅲ,10株与近几年广东省内分离的PRRSV毒株QYYZ和GM2同属于亚群Ⅳ。PRRSV GP5基因的遗传进化分析结果表明,亚群Ⅲ和亚群Ⅳ是近几年在广东省内流行的新兴亚群,研究结果将为PRRSV疫苗的选择以及防控方案的制定提供参考。     

Genetic determination of phenotypic variation in sickle cell trait

Two genetic sources of variation influence the percentage of sickle cell hemoglobin found in heterozygotes. One factor is strongly related to the percentage of hemoglobin S in the carrier parent and appears to be determined by sickle hemoglobin isoalleles, whereas the other is related to racial background and may well be polygenic.     

Genetic variation affects de novo translocation frequency

Translocation is one of the most frequently occurring human chromosomal aberrations. The constitutional t(11;22)(q23;q11), which is the only known recurrent non-Robertsonian translocation, represents a good model for studying translocations in humans. Here we demonstrate polymorphisms of the palindromic sequence at the t(11;22) breakpoint that affect the frequency of de novo translocations in sperm from normal males. A typical allele consists of a perfect palindrome, producing ~10-5 de novo t(11;22) translocations. Alleles with an asymmetric center do not form the t(11;22). Our data show the importance of genome sequence on chromosomal rearrangements, a class of human mutation that is thought to be random.     

Genetic mapping in human disease

Genetic mapping provides a powerful approach to identify genes and biological processes underlying any trait influenced by inheritance, including human diseases. We discuss the intellectual foundations of genetic mapping of Mendelian and complex traits in humans, examine lessons emerging from linkage analysis of Mendelian diseases and genome-wide association studies of common diseases, and discuss questions and challenges that lie ahead.     

Genetic variation in coumarin hydroxylase activity in the mouse (Mus musculus)

Basal and phenobarbital-induced rates of hepatic metabolism of coumarin to 7-hydroxycoumarin are markedly higher in DBA/2J mice than they are in the AKR/J, C57BL/6J, and C3H/HeJ strains. Intermediate coumarin hydroxylase activity in F(1) hybrids of mating between DBA/2J and the other three strains indicates an additive mode of inheritance.     

H9N2禽流感病毒陕西分离株HA基因的遗传变异分析

【目的】对H9N2禽流感病毒HA基因全序列进行分析,了解H9N2禽流感分离毒株HA基因的遗传变异情况。【方法】根据GenBank已发表的H9N2毒株的基因序列,设计了2对H9N2禽流感病毒HA基因特异性引物,运用RT-PCR方法对XL、LF和WN分离株进行了扩增,然后将PCR产物送出进行测序,用DNAstar 5.0软件对测序结果进行了分析。【结果】XL、LF和WN 3株H9N2分离株间HA基因的核苷酸同源性为99.7%~99.9%,推导氨基酸的同源性为99.1%~99.6%;分离株与参考毒株HA基因核苷酸的同源性为96.2%~99.0%,推导氨基酸的同源性为96.2%~98.6%。通过对3个H9N2分离株间HA基因核苷酸序列的比较,发现共有5个位点的核苷酸发生突变,其中4个位点核苷酸的改变导致相应的氨基酸发生突变。HA蛋白的7个受体结合位点比较保守,但是其在551~553位缺失了潜在的糖基化位点。【结论】3株H9N2分离株裂解位点氨基酸序列完全符合低致病性禽流感的特征RSSR↓G,但是LF裂解位点附近333位脯氨酸(Pro)突变为组氨酸(His),即非极性氨基酸向极性带正电氨基酸(碱性氨基酸)转变,裂解位点的变化可能是H9N2禽流感病毒生物学特性改变的分子基础。     

甘蔗有性世代单叶净光合速率的遗传变异性

研究了甘蔗F1代10个家系单叶净光合速率（Pn）的遗传趋势．结果表明,Pn的表型分布近似正态分布．属于数量性状遗传,受微效多基因控制．广义遗传力（h2B）较低,为21．58％～30．68％,因此在低世代对Pn的选择应适当降低选择强度并根据与Pn密切相关的性状进行筛选．不同家系遗传标准差和遗传变异系数有所差异,家系选15×崖90／31、粤农85／177×崖90／31和CP72／1210×崖90／31的Pn平均值较高且遗传变异系数较大,从这些家系中选择高光效基因型的效果好,可获得较高的遗传进展．     

山东省小麦品种高分子量谷蛋白亚基遗传变异分析

对山东省 2 0世纪 6 0年代以来育成推广的 6 0个小麦品种的高分子量谷蛋白亚基的遗传变异进行了分析 ,并分析了亚基和面粉品质的关系。结果表明 :在所研究的小麦品种中 ,Glu -1位点具有较丰富的遗传变异类型 ,共有 1 3种亚基类型和 2 2种亚基组成模式。各亚基出现频率不尽相同 ,A1位点上的 1亚基出现频率为 5 0 0 % ,B1位点上 7+ 8亚基出现频率为 4 8 3% ,D1位点上 2 + 1 2亚基出现频率为 6 5 0 %。亚基 1 ,2+ 1 2 ,7+ 8模式出现频率最高 ,同时出现了含有 2 + 1 0亚基的新的亚基组成模式。优质亚基 5 + 1 0仅在 80年代以后选育推广的小麦品种中存在 ,且 5 + 1 0亚基出现频率和高分子量谷蛋白亚基品质评分均呈现上升趋势。亚基 7+ 9、1 3+ 1 6、5 + 1 0均对沉降值和谷蛋白大聚体 (GMP)含量有显著的正向作用     

北京褐斯坦奶牛中四个微卫星座位的遗传变异

利用4个微卫星座位BM1818，BM1258，BM1443和BM1905，对240头北京褐斯坦奶牛进行了遗传检测，计算了4个微卫星座位的等位基因频率、多态信息含量、有效等位基因数、杂合度，其中BM1443的遗传变异最大，BM1818的最小。     

7株新城疫病毒V基因遗传变异与病毒的基因分型

测定了7株不同来源不同毒力新城疫病毒的V基因,并对它们的差异性和遗传进化关系进行了比对分析.结果显示:7株病毒V基因之间的核苷酸同源性为81.7%-99.7%,推导氨基酸残基的同源性为75.8%-99.6%;遗传进化分析显示,7株病毒分别处在3个不同的进化分支上,毒力相似的毒株聚类在同一进化分支上,而这与基于F基因的基因分型一致.由结果可推测,新城疫病毒V基因可能与F基因具有相似的遗传变异率,V基因也适合作为病毒基因分型分析的候选靶基因.     

Paired-end mapping reveals extensive structural variation in the human genome

Structural variation of the genome involves kilobase- to megabase-sized deletions, duplications, insertions, inversions, and complex combinations of rearrangements. We introduce high-throughput and massive paired-end mapping (PEM), a large-scale genome-sequencing method to identify structural variants (SVs) approximately 3 kilobases (kb) or larger that combines the rescue and capture of paired ends of 3-kb fragments, massive 454 sequencing, and a computational approach to map DNA reads onto a reference genome. PEM was used to map SVs in an African and in a putatively European individual and identified shared and divergent SVs relative to the reference genome. Overall, we fine-mapped more than 1000 SVs and documented that the number of SVs among humans is much larger than initially hypothesized; many of the SVs potentially affect gene function. The breakpoint junction sequences of more than 200 SVs were determined with a novel pooling strategy and computational analysis. Our analysis provided insights into the mechanisms of SV formation in humans.