Comparative analysis of the pig BAC sequence involved in the regulation of myostatin gene

Myostatin (GDF-8, MSTN) is a member of trans- forming growth factors (TGF-β) superfamily, which was first described by McPherron et al. in 1997[1]. Myostatin appears to act as a negative regulator of muscle development and controls not only fibre size but also fibre number[2,3]. Mutations in the third exon of the myostatin gene have been shown to cause dou- ble muscling in cattle[4]. By knocking out the gene of myostatin in mice, they were able to show that the transgenic mice developed …     

醛糖还原酶基因5′调控区新的点突变对基因表达调控的影响

为了进一步研究醛糖还原酶 (AR)基因 5′调控区存在的可引起蛋白质表达发生改变的遗传变异及其对糖尿病并发症的影响 ,应用PCR SSCP对中国人 2型糖尿病患者的AR基因 5′调控区进行筛选 ,在两名糖尿病患者中发现一新点突变C- 1 6 7→A ,使AR基因 5′调控区产生一个新的CCAAT盒。含点突变的两名患者尽管患病多年 ,长期处于高血糖状态 ,但无糖尿病并发症发生。而且他们的红细胞中AR活性都很低 ,处于无视网膜病变患者组的下限范围。将含野生型和点突变DNA片段分别克隆至氯霉素乙酰转移酶报告基因载体 (pCAT) ,检测CAT的活性确定野生型和突变型序列的转录活性。同时进行凝胶滞留试验以观测DNA与蛋白质的相互作用。结果显示 :含C- 1 6 7→A的启动子相对转录活性 (5 .7% )明显低于野生型(15 .7% )。凝胶滞留试验中 ,突变序列迁移速率较野生型慢。以上结果说明 ,AR基因 5′调控区C- 1 6 7→A点突变干扰了启动子区顺式作用元件与反式作用因子的结合 ,导致AR基因转录活性降低 ,使患者组织中AR活性下降 ,从而阻止或减缓 2型糖尿病视网膜病变发生发展。     

脑胶质瘤患者组织和血清MGMT、hMLH1和hMSH2基因启动子甲基化状态检测

目的探讨脑胶质瘤患者组织和血清中MGMT、hMLH1和hMSH2基因启动子CpG岛甲基化发生率及相关性。方法甲基化特异性PCR（MSP）检测39例脑胶质瘤组织样本及32例预处理的脑胶质瘤血清样本中MGMT、hMLH1和hMSH2基因启动子区的甲基化状态。结果脑胶质瘤组织MGMT、hMLH1和hMSH2基因启动子区甲基化发生率分别为46．2％、10．3％和20．5％,肿瘤组织中至少有一种基因甲基化的发生率为64．1％（25／39）;在脑胶质瘤患者外周循环血液中检测到了相关基因甲基化系列,并且与组织中基因甲基化发生率明显相关。结论MGMT、hMLH1和hMSH2基因启动子甲基化是脑胶质瘤发生过程中常见的分子事件,血清中相关基因DNA甲基化检测有可能为脑胶质瘤诊断和个体化化疗提供一种稳定的无创性检测指标。     

关于中国淡水生态系统生物多样性监测与管理的探讨

China is one of the countries in the world with therichest species biodiversityinfreshwater ecosystem.How-ever,duetothe rapid economic growthandthe continuingincrease of human disturbances and destructions of aquatichabitats,the biodiversity of freshwater ecosystemsis dras-tically declining.Waterbodies become more and more“deserted”of sensitive species.Water areas are reduced,fragmentized,and changed in their hydrodynamics(i.e.damming),causing changes in sedimentation and otherchanges.Forinstance,the area o...     

西藏农牧民生态足迹

基于相关的统计年鉴,采用综合法对2000-2012年西藏农牧民的生态足迹与生态承载力进行分析.结果表明： 研究期间,研究区农牧民生态状况均表现为生态盈余,但其盈余量呈逐年下降趋势;生态承载力由2000年的7.49 hm²下降到2012年的6.35 hm²,降幅达15.3%;生态足迹呈波动式逐渐增加趋势,由2000年的1.03 hm²增加到2012年的1.26 hm².
     

Excess of de novo deleterious mutations in genes associated with glutamatergic systems in nonsyndromic intellectual disability

Little is known about the genetics of nonsyndromic intellectual disability (NSID). We hypothesized that de novo mutations (DNMs) in synaptic genes explain an important fraction of sporadic NSID cases. In order to investigate this possibility, we sequenced 197 genes encoding glutamate receptors and a large subset of their known interacting proteins in 95 sporadic cases of NSID. We found 11 DNMs, including ten potentially deleterious mutations (three nonsense, two splicing, one frameshift, four missense) and one neutral mutation (silent) in eight different genes. Calculation of point-substitution DNM rates per functional and neutral site showed significant excess of functional DNMs compared to neutral ones. De novo truncating and/or splicing mutations in SYNGAP1, STXBP1, and SHANK3 were found in six patients and are likely to be pathogenic. De novo missense mutations were found in KIF1A, GRIN1, CACNG2, and EPB41L1. Functional studies showed that all these missense mutations affect protein function in cell culture systems, suggesting that they may be pathogenic. Sequencing these four genes in 50 additional sporadic cases of NSID identified a second DNM in GRIN1 (c.1679_1681dup/p.Ser560dup). This mutation also affects protein function, consistent with structural predictions. None of these mutations or any other DNMs were identified in these genes in 285 healthy controls. This study highlights the importance of the glutamate receptor complexes in NSID and further supports the role of DNMs in this disorder.     

褐飞虱成虫体内磁性物质检测

地磁定向是昆虫远距离迁飞定向的重要机制之一.本研究以褐飞虱Nilaparvata lugens长翅型和短翅型成虫为研究对象,利用MPMS-7型号超导量子干涉磁强计(磁场范围为±4.8 mA/m,温度范围为1.9 ～ 400 K)检测虫体内的磁性物质,明确其体内的分布状况.结果表明:褐飞虱长翅型雄成虫整个虫体的温度退磁曲...     

社鼠（Niviventer confucianus）线粒体基因组全序列分析

社鼠（Niviventer confucianus）属于啮齿目（Rodentia）、鼠科（Muridae）、白腹鼠属（Niviventer）,关于该物种的分子系统学研究极少。为获取社鼠线粒体基因组全序列,提取其基因组总DNA,参照近缘物种线粒体基因组全序列设计34对特异性引物,利用PCR扩增全部片段后进行测序,之后对其基因组组成及结构特点进行了初步分析。结果表明,社鼠线粒体基因组全序列长16 281 bp（GenBank收录号：KJ152220）,包含22个tRNA基因、13个蛋白质编码基因、2个rRNA基因和1个非编码控制区;基因组核苷酸组成为34.0%A、28.6%T、24.9%C、12.5%G。将所得序列与社鼠近缘物种（川西白腹鼠、小家鼠、褐家鼠）的线粒体全基因组进行比较,结果显示,四个物种的线粒体基因组虽然在基因组大小、部分tRNA二级结构、部分蛋白质编码基因的起始或终止密码子及控制区长度和碱基组成上有差异,但基因组结构和序列特征方面都具有较高的相似性。四个物种线粒体全基因组间的遗传距离显示,社鼠与川西白腹鼠距离最近,而与小家鼠距离最远。该研究为利用线粒体全基因组信息进行啮齿类分子系统学研究提供了有价值的资料。