广州地区106例汉族人群MICA和MICB微卫星基因座 单体型研究 The Study on the Haplotype of MICA and MICB Microsatellite Locus In Guangzhou Han Population

利用聚合酶链反应和荧光（6－FAM）自动化检测技术对广东地区汉族106例无亲缘关系样本进行MICA基因外显子5和MICB基因内含子1微卫星基因座多态性及其单体型分布调查。根据群体资料估算两者间的单体型频率、连锁不平衡参数、相对连锁不平衡参数。结果显示，广州地区汉族人群MICA和MICB微卫星基因座基因型分布符合Hardy-Weinberg平衡法则，共检出MICA微卫星基因座 5个等位基因， MICB微卫星基因座14个等位基因。其中MICA A5基因频率最高（0.2877），A4基因频率最低（0.1321）。MICB CA14等位基因频率最高（0.3255），CA19、CA28等位基因频率最低（0.0047），未检出CA27。21种MICA－MICB单体型频率大于1%(连锁不平衡参数>0), 其中单体型A5－CA14 (16.73%), A5.1－CA18 (8.75%), A4－CA26(3.76%)，A9－CA15(3.66%)和A6－CA21(2.61%)为强连锁常见单体型（χ2>3.84, P<0.05）。广州地区汉族人群MICA和MICB微卫星基因座多态性和单体型分布有其自身特点，MICA和MICB微卫星基因座适合做为遗传标志，用于人类学、遗传疾病基因连锁分析、法医学亲子鉴定和个体识别等研究领域。Abstract: This study is to investigate genetic polymorphisms and haplotypes of microsatellite locus in the exon 5 of the MICA gene and intron 1 of the MICB gene based on 106 samples of Guangzhou Han Population by polymerase chain reaction and fluorescent technique (6-FAM). The corresponding haplotype frequencies, linkage disequilibria values and relative linkage disequilibria values were estimated based on population data. The results show that the genotype distributions of MICA and MICB microsatellite meet Hardy-Weinberg equilibrium in Guangdong Han population. In total, 5 alleles of MICA microsatellite locus and 14 alleles of MICB microsatellite locus were observed. MICA A5 was the most common allele (0.2877), whereas A4 was the least popular one (0.1321). MICB CA14 was the most common allele (0.3255), and CA19 and CA28 were the least popular ones (0.0047). CA27 was not observed. Twenty-one kinds of MICA-MICB haplotypes occurred at frequencies of more than 1% (linkage disequilibria value>0). The common MICA-MICB haplotypes were A5-CA14（16.73％）, A5.1- CA18 (8.75%), A4- CA26(3.76%)，A9-CA15(3.66%) and A6-CA21(2.61%)（χ2>3.84, P<0.05）, and they were strong linkage disequilibria. The polymorphisms and haplotypes distributions of MICA and MICB microsatellite locus in Guangzhou Han population have their own genetic characteristics. The microsatellite locus of the exon5 of the MICA gene and intron 1 of the MICB gene could be used as the genetic markers in the studies of anthropology, linkage analysis of genetic disease genes, individual identification and paternity test in forensic medicine.     

被子植物多胚苗的研究进展

本文综述了被子植物多胚苗的研究进展。在被子植物中多胚苗材料的种类很多,而只有特定起源的多胚苗材料在作物杂种优势固定中才具有比较大的实用价值。关于被子植物多胚苗的发生机理目前还没形成统一的定论。单倍性、二倍性和多倍性多胚苗在作物育种上具有各自不同的意义。     

DNA序列分析与计算机的应用

研究核酸结构和功能相互关系的各种规律,这是科学工作者的基本目标。对分子生物学家来说,这意味着去弄清核酸序列中所包含的信息。这就是说要去分析和介绍这些序列的真正含义。由于大部分DNA分子实在太长,长期以来严重地妨害了我们对DNA分子进一步研究的种种努力。幸而,人们发现了限制性内切酶,这种酶可以把DNA大分     

光温外界信号、植株状态与成花决定

植物由营养生长状态转向生殖生长状态（成花转变）是发育过程中的重要一步。经过一段时期营养生长的植株,便自动进入成花感受态,在这种状态下植株才能够对外界信号产生应答反应而启动成花过程。本文主要讨论光周期和温度对成花的作用     

通过异倍性水稻间杂交获得同源三倍体植株

以３个二倍体水稻（ＯｒｙｚａｓａｔｉｖａＬ．）（２ｎ＝２ｘ＝２４）和３个同源四倍体水稻（２ｎ＝４ｘ＝４８）为杂交亲本配制６个自交组合和３０个杂交组合,试验结果表明,同源四倍体组合的结实率比较低（１０．０１％－２１．７８％）这可能与其花药内民包含的正常花粉粒比例小而异常花粉粒比例大有关,异倍性杂交组合的结实率更低（０．２０％－１．６４％）但在两种配组方式之间却存在着明显差异,即以同源四倍体水稻为杂交     

纳米Fe3O4对生菜生长及土壤细菌群落结构的影响

纳米Fe₃O₄的广泛应用增加了其暴露到农田环境的可能性,因此亟待研究纳米Fe₃O₄对农业生态环境的影响.本研究采用盆栽试验方式,研究不同浓度纳米Fe₃O₄颗粒(1、10、100 mg·kg^-1)对生菜生长及土壤细菌群落的影响,并与相应浓度的普通Fe₃O₄处理进行对比.通过测定植物光合速率常数、植株Fe含量来评价植物生长;采用高通量测序技术研究土壤细菌群落结构及组成.结果表明: 不同浓度纳米Fe₃O₄的影响不同.低浓度纳米Fe₃O₄能提高植物生物量,增强植物叶片光合速率,增加土壤中黄单胞菌目的相对丰度,降低蓝细菌、鞘脂杆菌纲的相对丰度,但对群落多样性指数影响不显著.高浓度纳米Fe₃O₄抑制作物生长,提高植株中Fe积累及土壤电导率,降低细菌群落系统发育多样性,降低黄单胞菌目、鞘脂杆菌纲相对丰度,增加蓝细菌相对丰度.此外,一些土壤功能微生物对纳米Fe₃O₄及普通Fe₃O₄处理的响应也存在差异,说明不同粒径及浓度的Fe₃O₄均会对土壤微生物群落产生影响,并可能影响地上部分植物性状.因此,在评估纳米颗粒的生物学效应时需较多关注土壤微生物.     

Tyroserleutide tripeptide affects calcium homeostasis of human hepatocarcinoma BEL-7402 cells

Copyright by Science in China Press 2005 Primary hepatocarcinoma is one of the most fre-quent digestive-tract cancers, particularly in China. The incidence and death rate of primary hepatocarci-noma in China is the highest in the world, with about 1100 thousands people dying from primary hepatocar-cinoma per year[1]. Although the chemotherapeutic agents are the main therapeutic approach for hepato- carcinoma, they are relatively ineffective and result in many toxic and side effects. Accordin…     

辣椒种子的超干研究

辣椒种子含水量(MC)降至5％以下,能显著提高抗老化劣变的能力。在同等老化处理(50C15d)后,对照种子(MC=7．5％)发芽势已大幅度下降,而超干种子(MC=4．1％～1．4％)的发芽势与未老化种子相同。超干种子脱氢酶活性明显高于同等老化条件下的对照种子,而丙二醛的含量则显著低于对照种子。电导率测定结果表明,超干种子细胞膜系统的完整性良好。     

采用植物离体培养技术生产精油

本文对近三十年来采用植物离体培养技术生产精油的研究进展作了介绍。     

Herbaspirillum seropedicae rfbB and rfbC genes are required for maize colonization

In this study we disrupted two Herbaspirillum seropedicae genes, rfbB and rfbC, responsible for rhamnose biosynthesis and its incoporation into LPS. GC-MS analysis of the H. seropedicae wild-type strain LPS oligosaccharide chain showed that rhamnose, glucose and N-acetyl glucosamine are the predominant monosaccharides, whereas rhamnose and N-acetyl glucosamine were not found in the rfbB and rfbC strains. The electrophoretic pattern of the mutants LPS was drastically altered when compared with the wild type. Knockout of rfbB or rfbC increased the sensitivity towards SDS, polymyxin B sulfate and salicylic acid. The mutants attachment capacity to maize root surface plantlets was 100-fold lower than the wild type. Interestingly, the wild-type capacity to attach to maize roots was reduced to a level similar to that of the mutants when the assay was performed in the presence of isolated wild-type LPS, glucosamine or N-acetyl glucosamine. The mutant strains were also significantly less efficient in endophytic colonization of maize. Expression analysis indicated that the rfbB gene is upregulated by naringenin, apigenin and CaCl(2). Together, the results suggest that intact LPS is required for H. seropedicae attachment to maize root and internal colonization of plant tissues.