甘肃南部双盾木属植物的ISSR分析

采用ISSR技术分析了甘肃南部分布的4种双盾木的遗传多样性和遗传分化．根据研究结果,指出4种双盾木属总的多态位点百分率（PPB）很高,达100％。其遗传多样性很丰富,但在种间的分布是不均匀的,结果与Nei’s基因多样度和Shahnon信息指数的遗传多样性分析结果一致,根据非加全算术平均聚类法以及ISSR特征图谱可以将不同种区分开来,得出ISSR分子标记可很好地用于双盾木属的分子鉴定和遗传背景研究的结论。     

一种带有表型标记基因的诱导型抗旱植物表达载体的构建

为了克服组成型表达转录因子基因影响转基因植物性状的缺点,并构建一种具有级联放大作用并带有表型标记的诱导型植物双价表达载体。研究采用PCR方法从拟南芥克隆获得冷诱导转录因子CBF3基因,蜡质合成相关WIN1基因,干旱诱导RD29A基因启动子和冷诱导的LEA14基因启动子,并用CBF3转录因子所调控的下游RD29A基因启动子和LEA14基因启动子分别驱动CBF3基因和W1N1基因表达,构建了双价植物表达载体RD29AP-CBF3／LEA14P—WIN1／pcAMBIA2201。我们预测在转基因植物中,该表达系统可在干旱等逆境信号存在条件下,通过级联放大的方式诱导表达,在增加植物抗逆性的同时,增加叶片表层蜡质的积累,从而易于表型识别。本研究为利用花粉管通道法转化棉花,提高抗逆转基因棉花田间筛选的效率奠定了基础。     

语用标记语与英语阅读教学模式设计

国内外很多学者的研究证明语用标记语对于英语阅读有促进作用。文章利用语用标记语对英语阅读教学模式进行了设计，并通过实验证明了这种新的教学模式可以让学生更注意英语阅读文章的宏观结构和重点信息，从而提高阅读的速度和效率。     

血清miR-25、miR-223和miR-373作为食管鳞癌生物标志物的评价

为了探讨血清miRNA作为诊断标志物的可行性,利用茎环引物进行qRT-PCR,检测了miR-25、miR-223和miR-373在正常人血清、食管鳞癌患者术前和术后第7 d血清、癌组织和癌旁组织的相对表达量.实验结果表明:术前食管鳞癌病人的3种血清miRNA相对表达量高于正常人和手术后第7 d病人,AUC分别为0.794、0.839和0.873,癌组织的这3种miRNA相对表达量高于癌旁组织.这3种miRNA在食管癌患者癌组织的高表达导致血清的这3种miRNA含量增高,因此这3种血清miRNA可以作为候选诊断标志物.     

Inter- and intrapopulation studies of ancient humans

For a genetic analysis of ancient human populations to be useful, it must be demonstrated that the DNA samples under investigation represent a single human population. Toward that end, we have analyzed human DNA from the Windover site (7000–8000 BP). MHC-I analysis, using allele-specific oligonucleotide hybridization to PCR amplified Windover DNA, microsatellite analysis by PCR of the APO-A2 repeat and mtD-loop 3 region sequencing on multiple individuals spanning nearly the full range of estimated burial dates all confirm the hypothesis that there is a persistence of both nuclear and mitochondrial haplotypes at Windover throughout its entire period of use. Thus, Windover can be considered a single population. Neighbor-joining tree analysis of mtDNA sequences suggests that some mitochondrial types are clearly related to extant Amerind types, whereas others, more distantly related, may reflect genetically distinct origins. A more complete sequence analysis will be required to firmly resolve this issue. Calibrating genetic relationships deduced by tree analysis, radiocarbon dates and burial position, yields a human mtD-loop DNA rate of evolution of 3700 to 14,000 years per percent change. Both values are within the range of recent, independently calculated values using estimates of evolutionary divergence or theoretical population genetics. Thus we are beginning to relaize the promise of ancient DNA analysis to experimentally answer heretofore unapproachable questions regarding human prehistory and genetic change.     

Population genetic structure and mating system evolution in freshwater pulmonates

Freshwater gastropods (Basommatophora and Prosobranchia) harbor a variety of mating systems. In particular, apomictic parthenogenesis in prosobranchs and self-fertilization in the hermaphrodite pulmonates may be viable alternatives to outcrossing sexuality in a number of species. The coexistence of different mating systems in extant populations provides opportunities to examine the forces directing their evolution. We review the models analyzing and predicting genetic variability in subdivided populations, with an emphasis on the effects of inbreeding. Population genetic data on freshwater pulmonates are examined in the context of selfing rates and the loss of variability under selfing. Furthermore, the genetic and demographic factors thought to influence mating system evolution are considered, and we highlight the different approaches available to estimate mating system parameters, in particular the selfing rate. Recent population biological studies on polyploid species (Bulinus truncatus, Ancylus fluviatilis) indicate that selfing is the predominant mating system. These studies have contributed to a deeper understanding of conceptual issues in the evolution of selfing rates. Throughout, we emphasize the need for further carefully designed studies.     

Further molecular evidence for the Hordeum vulgare ssp. spontaneum in Tibet as ultimate progenitor of Chinese cultivated barley

106 aeeessions of Tibetan wild barley, including 50 accessions of the two-rowed wiht barley Hordeum vulgare ssp. sopntaneum （HS）, 27 accessions of the six-rowed bottle-shaped wild barley H. lagunculiforme （HL） and 29 accessions of the six-rowed wiht barley H. agriocrithon （HA） that separately represent different agrigeographical regions of Tibet, were used to study the genetic diversity and genetie differentiation using SSR markers selected from seven barley linkage groups. 229 allelic variants were identified with an average of 7.6 alleles/locus. The average of total number of alleles per locus in HA （6.4） is much higher than that in HS （3.9） and HL （3.4）. The genetie diversity and its standard deviation among the three subspecies were in the order of HS〉HL〉HA. Very significant genetic differentiation was observed among the three subspecies of wild barley. Comparisons of the results fiom this and previous studies showed a strong Oriental-Occidental differentiation of barley, and that Shannan region of Tibet might be the center of origin of the Tibetan two-rowed wild barley, thus supporting not only the hypothesis of a mono-phyletie origin of cultivated barley but also the proposition that the Tibetan two-rowed wild barley as ultimate progenitor of Chinese cultivated barley.     

Genetic analysis of gynogenetic and common populations of Verasper moseri using SSR markers

The genetic structure and variation of the artificial meio- gynogenetic population and common population of barfin flounder (Verasper moseri) were analyzed using eight microsatellite markers. A total of 29 alleles were detected, of which 23 alleles were in the artificial gynogenetic population while 29 alleles were in the control group. The average observed heterozygosity (H _O) of eight loci in the control group (0.526 8) was several times higher than that (0.185 8) in the gynogenetic population. The results indicate that the genetic diversity of the control group was much higher than that of the gynogenetic population of barfin flounder (Verasper moseri). Most loci significantly deviated from Hardy-Weinberg equilibrium (HWE) after Bonferroni correction (p < 0.005 56) in the gynogenetic population, while four loci deviated from HWE in the control group. The coefficient of gene differentiation (G _ST) was 0.131 0, and the genetic distance was 0.171 8 between the two populations, suggesting a significant genetic differentiation between the two populations. Biography: MA Hongyu (1979–), male, Ph. D. candidate, research direction: marine biotechnology and molecular genetics.     

条斑紫菜不同栽培品系的遗传多样性分析

【目的】确定通过杂交和突变选育出的条斑紫菜(Pyropia yezoensis)栽培品系的遗传多样性。【方法】采用简单重复序列区间(Inter simple sequence repeat,ISSR)、扩增片段长度多态性(Amplified fragment length polymorphism,AFLP)和随机扩增多态性DNA(Random amplified polymorphism DNA,RAPD)等3种分子标记对条斑紫菜不同栽培品系进行遗传多样性分析。【结果】3种分子标记的多态性比率分别为38.10%、38.95%和61.75%;所表现出来的不同栽培品系间遗传距离分别为0.1785,0.1029和0.2845;3种分子标记聚类结果并不完全一致,但可以看出Y-0602、Y-HA01和Y-H001总是聚类在一起,而Y-DL02倾向于单独聚为一支。【结论】通过诱变和杂交所选育的品系,在遗传角度上仍然属于条斑紫菜,但已形成不同栽培品系,具有一定的遗传多样性。     

利用ISSR分子标记研究樱桃李野生类型的遗传多样性及亲缘关系

利用ISSR分子标记技术对产于中国天山的40个樱桃李(Prunus divaricata Ldb.)野生类型遗传多样性进行研究。通过遗传多样性研究及UPGMA聚类分析显示,野生樱桃李种下类群间遗传多样性有差异,平均多样性指数(I)为0.488,遗传相似系数(Hs)介于0.504~0.851之间,平均为0.678,遗传距离(GD)的范围在0.127 0~0.604 2之间,等位基因数(Na)和有效等位基因数(Ne)分别为1.908和1.571,而平均Nei基因多样性指数为0.17,平均Shannon信息指数(I)为0.22则显示其群体遗传多样性较低;分子标记下的聚类结果,可将中国天山产的40个樱桃李野生类型归为4大类,结合形态学特征分析,研究表明中国天山的40个野生樱桃李可划分为4个变种,即矮生樱桃李P.divaricata var.humila(N.R.Cui et L.Wang)D.F.Cui,comb.nov.、黑果樱桃李P.divaricata var.nigrooarp(N.R.Cui et L.Wang)D.F.Cui,comb.nov.、红果樱桃李P.divaricata var.phoenicea(Z.Xu)D.F.Cui,comb.nov.和黄果樱桃李P.divaricata var.luteola(N.R.Cui)D.F.Cui,comb.nov.。