上海地区汉族人5-HT2a受体基因T102C多态性的基因频率分布

为了揭示中国汉族人5-HT2a受体基因T102C多态性基因频率的分布,我们随机抽取了226例汉族健康人作研究,用限制性片段长度多态性(RFLPs)技术测定研究对象的基因型和等位基因。结果发现汉族正常人5-HT2a受体基因T102C多态性基因型频率依次为:A1/A2=0.5044,A1/A1=0.2965,A2/A2 =0.1991,两种等位基因频率依次为:A1=0.5487,A2=0.4513,杂合度H=0.50 44、期望杂合度h=0.4953,多态信息量PIC=0.3726,表明T102C多态性具有合适信息,对疾病的关联研究,法医学鉴定有一定的价值。 Abstract:To investigate the distribution about genotype and allele frequencies of T102C polymorphism in the 5-HT2a receptor gene Chinese Han population,the genotypes and alleles of 226 healthy person were examined with Restriction Fragment Length Polymorphisms(RFLPs)technique.The genotype frequencies are as follows:A1/A2=0.5044,A1/A1=0.2965,A2/A2=0.1991,respectively,and the allele frequencies are as follows:A1=0.5487,A2=0.4513,respectively.The heterozygosity(H)is 0.5044,the expected heterozygosity(h)is 0.4953,and the Polymorphism Information Content(PIC)is 0.3726.Our findings suggest that the T102C polymorphism in 5-HT2a receptor gene may have suitable information to be used for association study or forensic identification.     

中国人群5—羟色胺2A受体基因中T102C多态性与精神分裂症的联系

在研究５－羟色胺２Ａ受体基因多态性与精神分裂症的关联分析中,调查了２０２例精神分裂症患者及２０２例正常对照。各相匹配组间比较未发现基因型和等位基因频率的显著性差异。结果提示,在中国人群中５－羟色胺２Ａ受体的静态Ｔ１０２Ｃ突变与精神分裂症之间不存在关联。     

重庆居民5-HT2A基因多态性与原发性高血压关系

以聚合酶链PCR法分析重庆市一般人群的5-HT2A基因C102T多态性(样本总数348人,其中高血压组:HT=137例,非高血压组:NT=211例)的临床指标间的相关性与频率分布。了解重庆地区汉族人群5-羟色胺受体2基因(5-hydroxytryptamine receptor gene,5-HT2A)C102T多态性与原发性高血压病(essential hypertension,EH)的关系。卡方检验结果显示5-HT2A的C102T基因多态性(P=0.549)与等位基因频率(P=0.263)在HT与NT之间没有显著性统计学差异;5-HT2A的C102T基因多态性与高血压logistic回归模型分析结果显示也未见显著性差异,卡方值(Wald)为0.399;比值比为0.884;95%的可信区间为0.603~1.296,P值为0.528。一般线性模型分析结果:5-HT2A基因C102T多态性与收缩压,舒张压之间没有显著性统计学差异,PSBP=0.868,PDBP=709。5-HT2A的C102T多态性可能与重庆汉族人群EH无关。     

组织蛋白酶D基因C224T多态与散发阿尔茨海默氏病的关联研究

组织蛋白酶D（Cathepsin D）是一种细胞核内体/溶酶体内的门冬酰胺蛋白酶。它有可能通过剪切淀粉样前体蛋白参与阿尔茨海默氏病（Alzheimer’s disease, AD）相关的神经退化。在以德国人为对象中的研究显示组织蛋白酶D基因（CTSD）C224T多态与AD发病风险紧密相关。然而,此结果未能在另一些群体中得到重复。为此,我们通过聚合酶链反应-限制性片段长度多态性方法分析了CTSD基因C224T多态性和载脂蛋白E（apolipoprotein E, ApoE）基因多态性在成都地区汉族老年人中的分布,探讨了CTSD C224T多态与散发AD的相关性。结果发现CTSD基因C224T多态分布在病例组与对照组之间没有显著性差异,提示成都地区汉族人群中CTSD基因C224T多态与散发AD不具有关联;但比值比的比较提示CTSD等位基因T和ApoEε4有弱的协同作用。Abstract: Cathepsin D is the major lysosomal/endosomal aspartic protease and exhibits β- and γ-secretase-like activity in vitro. Data from German suggest that the C224T polymorphism in the Cathepsin D gene (CTSD) exon 2 is strongly associated with the risk for Alzheimer’s disease (AD).Meanwhile other studies have not been able to replicate the result. It’s necessary to determine the genotype of the polymorphism in CTSD in Chinese sporadic AD patients and age-matched controls with normal cognition and examine possible association of the polymorphism with the disease. We find no strong evidence of association between the CTSD C224T polymorphism and Chinese sporadic AD. Whereas there may be a weak synergistic interaction between ApoE ε4 and CTSD T allele.     

共济失调蛋白2结合蛋白1基因多态性与奥氮平所致体重增加的关联研究

目的:既往研究表明,共济失调蛋白2结合蛋白1(A2BP1)基因多态性可能与精神分裂症、孤独症及肥胖等复杂疾病关联,但目前尚无相关文献提示A2BP1基因多态性与抗精神病药所致体重增加的关联.本研究拟探讨A2BP1基因多态性与奥氮平治疗精神分裂症所致体重增加的关联.方法:本研究共入组350例精神分裂症患者,其中完成奥氮平(治疗剂量5～20 mg/d)治疗8周者为328例.采用阳性与阴性症状量表(PANSS)减分率评估药物疗效;分别于治疗前和治疗8周后测量并记录患者的清晨空腹体重并计算治疗前后体重增加率(％).提取患者外周血DNA,采用DNA测序基因分析方法,在328例汉族精神分裂症患者中,检测A2BP1基因4个单核苷酸多态性(SNP)位点(rs8048076,rs1478697,rs10500331,rs4786847)的基因型,并采用数量性状位点分析方法(QTL)探索A2BP1基因多态性与奥氮平治疗所致体重增加率的关联.结果:A2BP1基因rs8048076 (T=3.237;P=0.0012)及rs1478697 (T=2.956;P=0.0032)位点与奥氮平治疗精神分裂症8周后所致体重增加率关联(P＜0.05),经多重检验Bonferroni校正后仍有统计学意义;而rs10500331 (T=-0.293;P=0.769)与rs4786847(T=0.666; P=-0.505)在本样本中与奥氮平所致体重增加的关联无统计学意义(P＞0.05).结论:本研究结果提示在中国汉族人群中,A2BP1基因多态性可能与奥氮平治疗精神分裂症患者所致体重增加副反应关联,如能进一步验证及机制探索,则有望在精神科个体化治疗方面对药物所致体重增加的预测与防治提供线索依据.     

抑郁症分子机制中5-羟色胺2C受体的作用

5-羟色胺系统与抑郁症关系密切,阐明5-羟色胺相关受体在抑郁症中的作用,有助于抗抑郁药物的开发与应用,提高抑郁症的治疗效果。在5-羟色胺的受体中,5-羟色胺2C受体(5-hydroxytryptamine type 2C receptor,5-HT2CR)在抑郁症的发病及治疗机制中发挥重要的作用。虽然已有关于5-羟色胺2C受体与抑郁症具有相关性的报道,但近年来,5-羟色胺2C受体参与抑郁症的相关分子机制有了新的进展,本文将抑郁症分子机制中5-羟色胺2C受体的作用加以综述,以期为相关工作提供依据。     

LPS—induced activation of phospholipase A2 phospholipase C and protein kinase C of murine macrophage—like cell lines （J774 and P388D1）

A murine macrophage-like cell line J774,acquired,in response to LPS,an ability to kill tumor necrosis factor(TNF)-insensitive target P815 mastocytoma cells whereas another cell line,P388D1 did not ,LPS triggered signaling mechanisms between the two cell lines were compared with an aim to inquire about the possible nature of the above-mentioned difference,The results whowed that two cell lines respond to LPS-treatment by parallel activation of both phospholipases C and A2 (PLC and PLA2) to approximately the same extent.The maximum response of toth enzymes of J774 cells was noted within 10 min the treatment whereas that of P388D1 cells required more than 20 min,The other properties of LPS-responsive enzymes studied were similar between two cell lines,including Activation of PLC and PLA2 and PKC in macrophages by LPS. Ca2 augmentation of enzyme activation,participation of guanine nucleotide binding(G) proteins in the initial activation preocesses,and inhibition of enzyme activation by the prior treatment of cells with choleraor pertussis toxinsetc.Moreover,LPS-triggered activation of PLC and PLA2 was found to be followed by the increase of PKC activities in both cell lines.Inspite of these similarities.J774 cells possessed both basic and acidicforms of PKC activities,while P 388 D1 cells owned only PKC of basic form,Nevertheless,the question why J774 cells but not P388D1 cells,can acquire the tumoricidal activity,aganist P815,cells following LPStreatment rematins to be answered.     

HTR2A基因多态性与云南彝族酒精依赖关联性研究

目的：探讨酒精依赖和云南彝族5-羟色胺2A受体（HTR2A）基因多态之间的关系。方法：采用PCR-RFLP技术对330健康人（对照组）和110名酒精依赖者（病例组）的5-HT2A受体基因的遗传多态性进行检测。结果：在440例样本中共检测到2种等位基因A和G,三种基因型AA,AG,GG．三种基因型在对照组中频率分别是38．5％,55．8％,5．8％;在病例组中的频率分别是30％,63．6％,6．4％。结论：在云彝族人群中,HTR2A基因rs6311（A－1438G）位点与酒精依赖无显著关联,HTR2A基因rs6311（A-1438G）位点在云南汉族和云南彝族酒精依赖组中无显著差异,但是在健康对照组中存在关联性．     

贵州苗族新生儿HbF中Gγ/Aγ比值测定与AγT基因频率分析

用含Triton X-100的酸性尿素聚丙烯酰胺凝胶电泳(PAGE)法测定了贵州省108例苗族新生儿脐带血胎儿血红蛋白(HbF)中Gγ/Aγ值.显示107例(占99.07%)新生儿的Gγ值在55-78%之间,均值与标准差为70.42±3.45;高Gγ值者1例(占0.925%);低Gγ值者未发现。用Large-pore Vydac C4柱反相高效液相层析法对108例样本进行了AγT基因频率（fAγT）分析,fAγT为0.0648。 The ratio of Gγ to Aγ of fetal hemoglobin inn 108 cord blood samples of Miao nationality newborns in Guizhou province was determined by the polyacrylamide gel electrophoresis(PAGE).The result showed that one case had high Gγ value(0.925%) and 107 babies the normal Gγ values of 55 to 78%(70.42+3.45)。The AγT gene frequency(fAγT) analysis in 108 samples was done by high pressure liquid chromatography using a large pore Vydac C4 column,the fAγT was 0.0648.     

犬MC1R基因T105A基因座多态性及 与毛色性状相关性的研究The

为了检测犬MC1R基因T105A基因座的多态性,并分析该多态性与犬毛色表型的相关性,抽取111只外科手术学实验用杂种犬血液并提取DNA,记录毛色表型。采用PCR-RFLP技术,对MC1R基因T105A基因座进行基因多态性分析,并对该基因座DNA进行克隆测序;用二元变量相关分析的统计学方法分析基因座多态性与毛色性状之间的相关性。经PCR-RFLP分析结果表明,T105A基因座序列具有多态性,表现为A、B二个等位基因和AA、AB及BB 3种基因型。A、B等位基因频率分别为72.97%和27.03%,基因杂合度（H）为0.39。基因型AA频率为55.86%,BB为9.91%,AB为34.23%。对T105A多态性片段DNA克隆测序后发现,MC1R基因在编码第105位氨基酸的密码子第一个碱基存在由G到A的单碱基突变,该突变导致第105位氨基酸发生由丙氨酸向苏氨酸的改变。统计分析结果表明MC1R基因T105A基因座的多态性与毛色性状不存在显著的相关性,这可能是由于外科手术学实验用犬是杂种犬,其遗传背景不同所致,尚须在纯种犬群体中进一步研究MC1R基因对毛色的影响。 Abstract: In order to detect the polymorphism of T105A in MC1R gene in dogs and to analyze the relationship between the genetic polymorphisms and phenotypes of dog coat color, the blood samples of 111 cross-breed dogs were taken and their genomic DNAs were extracted. The phenotypes of dog coat color were recorded. The T105A locus of MC1R gene in the canine was detected through the technology of PCR-RFLP. Furthermore, the polymorphic fragments at T105A were sequenced. The relationships between the polymorphism of T105A and coat color trait were analyzed by the statistical methods of bivarate correlation analysis. By the method of PCR-RFLP, the T105A polymorphism was found with two alleles A and B and three genotypes AA, AB and BB. The frequencies of two alleles were 72.97% and 27.03%, respectively. The heterozygosity of T105A locus was 0.39. The frequencies of three genotypes were 55.86%, 34.23% and 9.91%, respectively. According to the results of sequencing, one base change from G to A at the position 105 was found at T105A locus and it altered amino acid at the position 105 from alanine to threonine. According to the statistical analysis, no significant association between the polymorphism of MC1R gene and the coat color was found and the result may be due to the differences of genetic background. Further research on MC1R gene should be done in pure breed dogs.     

中国傣族、景颇族人群中与艾滋病相关的CCR5△32、CCR2b-64I、SDF1-3′A等位基因多态性分布

为了调查HIV-1感染相关的等位基因CCR5△32、CCR2b-64I、SDF1-3′A在我国云南省德宏州傣族景颇族人群中的频率和多态性分布,此课题以101例傣族和113例景颇族人群为研究对象,应用PCR、PCR-RFLP(聚合酶链反应-限制性片段长度多态性)分析方法进行检测,计算突变基因频率;并对其群体分布、性别分布进行统计学分析。结果表明,中国傣族景颇族人群中未发现CCR5△32等位基因突变;傣族CCR2b-64I、SDF1-3′A基因突变频率分别为0.2130和0.2030,景颇族CCR2b-64I和SDF1-3′A基因突变频率分别为0.1637和0.1770;与中国汉族人群相比较,傣族和景颇族中SDF1-3′A突变频率较低（P值分别为0.0322和0.0021）;两个民族的CCR2b-64I和SDF1-3′A等位基因群体分布符合Hardy-Weinberg平衡,在性别之间分布无显著差异。中国傣族景颇族人群的CCR2b-64I等位基因的突变频率与汉族人相似,SDF1-3′A等位基因的突变频率比汉族人低,此两种突变基因在艾滋病发病过程中的影响值得进一步研究。由于未发现CCR5△32基因突变,中国傣族景颇族人群对HIV-1感染可能有较大的遗传易感性。 Abstract:The purpose of the work is to investigate the frequencies and polymorphisms of HIV-1 resistant CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chinese Dai and Chingpaw populations.Whole blood samples from 101 Dai subjects and 113 Chingpaw were collected randomly and their genomic DNA were extracted with QIAgen Blood Kits.Allelic frequencies were identified by PCR-RFLP analysis.Allelic polymorphisms in Dai population or Chingpaw population and both sexes in the samples were analyzed by χ2 test.The frequencies of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Dai population were 0.0000,0.2130,0.2030,respectively;The frequencies of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chingpaw population were 0.000,0.1637,0.1770,respectively.Distributions of the CCR2b-64I,SDF1-3′A alleles among the both populations were in accordance with Hardy-Weinberg equilibrium.No statistical difference was found in the allelic frequencies of both CCR2b-64I and SDF1-3′A between male and female individuals.The frequencies of CCR5delta32,CCR2b-64I alleles in Chinese Dai and Chingpaw populations are similar to that in Chinese Han population,while the frequency of SDF1-3′A allele in Chinese Dai and Chingpaw populations are lower in contrast to that in Chinese Han population.The genotyping and polymorphism of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chinese Dai and Chingpaw populations of Yunnan Province are the first time studied in China.The significance of the three mutant alleles conferring genetic resistance to HIV-1 and AIDS progression remains to be clarified.     

中国傣族、景颇族人群中与艾滋病相关的CCR5△32、CCR2b-64I、SDF1-3′A等位基因多态性分布

为了调查HIV-1感染相关的等位基因CCR5△32、CCR2b-64I、SDF1-3′A在我国云南省德宏州傣族景颇族人群中的频率和多态性分布,此课题以101例傣族和113例景颇族人群为研究对象,应用PCR、PCR-RFLP(聚合酶链反应-限制性片段长度多态性)分析方法进行检测,计算突变基因频率;并对其群体分布、性别分布进行统计学分析。结果表明,中国傣族景颇族人群中未发现CCR5△32等位基因突变;傣族CCR2b-64I、SDF1-3′A基因突变频率分别为0.2130和0.2030,景颇族CCR2b-64I和SDF1-3′A基因突变频率分别为0.1637和0.1770;与中国汉族人群相比较,傣族和景颇族中SDF1-3′A突变频率较低（P值分别为0.0322和0.0021）;两个民族的CCR2b-64I和SDF1-3′A等位基因群体分布符合Hardy-Weinberg平衡,在性别之间分布无显著差异。中国傣族景颇族人群的CCR2b-64I等位基因的突变频率与汉族人相似,SDF1-3′A等位基因的突变频率比汉族人低,此两种突变基因在艾滋病发病过程中的影响值得进一步研究。由于未发现CCR5△32基因突变,中国傣族景颇族人群对HIV-1感染可能有较大的遗传易感性。 Abstract:The purpose of the work is to investigate the frequencies and polymorphisms of HIV-1 resistant CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chinese Dai and Chingpaw populations.Whole blood samples from 101 Dai subjects and 113 Chingpaw were collected randomly and their genomic DNA were extracted with QIAgen Blood Kits.Allelic frequencies were identified by PCR-RFLP analysis.Allelic polymorphisms in Dai population or Chingpaw population and both sexes in the samples were analyzed by χ2 test.The frequencies of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Dai population were 0.0000,0.2130,0.2030,respectively;The frequencies of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chingpaw population were 0.000,0.1637,0.1770,respectively.Distributions of the CCR2b-64I,SDF1-3′A alleles among the both populations were in accordance with Hardy-Weinberg equilibrium.No statistical difference was found in the allelic frequencies of both CCR2b-64I and SDF1-3′A between male and female individuals.The frequencies of CCR5delta32,CCR2b-64I alleles in Chinese Dai and Chingpaw populations are similar to that in Chinese Han population,while the frequency of SDF1-3′A allele in Chinese Dai and Chingpaw populations are lower in contrast to that in Chinese Han population.The genotyping and polymorphism of CCR5delta32,CCR2b-64I,SDF1-3′A alleles in Chinese Dai and Chingpaw populations of Yunnan Province are the first time studied in China.The significance of the three mutant alleles conferring genetic resistance to HIV-1 and AIDS progression remains to be clarified.     

Phosphatidic Acid （PA） PP2A Activity and PIN1 Binds PP2AA1 to Regulate Polar Localization

Phospholipase D （PLD） exerts broad biological functions in eukaryotes through regulating downstream effectors by its product, phosphatidic acid （PA）. Protein kinases and phosphatases, such as mammalian target of rapa- mycin （mTOR）, Protein Phosphatase 1 （PP1） and Protein Phosphatase 2C （PP2C）, are PA-binding proteins that execute crucial regulatory functions in both animals and plants. PA participates in many signaling pathways by modulating the enzymatic activity and/or subcellular localization of bound proteins. In this study, we demonstrated that PLD-derived PA interacts with the scaffolding A1 subunit of Protein Phosphatase 2A （PP2A） and regulates PP2A-mediated PIN1 dephos- phorylation in Arabidopsis. Genetic and pharmacological studies showed that both PA and PP2A participate in the regu- lation of auxin distribution. In addition, both the phosphorylation status and polar localization of PIN1 protein were affected by PLD inhibitors, Exogenous PA triggered the membrane accumulation of PP2AA1 and enhanced the PP2A activity at membrane, while PLD inhibition resulted in the reduced endosomal localization and perinuclear aggregation of PP2AA1. These results demonstrate the important role of PLD-derived PA in normal PP2A-mediated PIN dephosphoryl- ation and reveal a novel mechanism, in which PA recruits PP2AA1 to the membrane system and regulates PP2A function on membrane-targeted proteins. As PA and PP2A are conserved among eukaryotes, other organisms might use similar mechanisms to mediate multiple biological processes.     

新疆蒙古族、锡伯族新生儿HbF中Gγ/Aγ、AγI/AγT比值测定及基因图谱分析

用HPLC法测定新疆蒙古族78例、锡伯族60例新生儿胎儿血红蛋白(HbF)中Gγ/Aγ以及AγI/AγT比值。%Gγ均值为:蒙古族73.99% ,锡伯族74.59%。%AγI均值分别为蒙古族56.04%和锡伯族64.33%。在蒙古族中发现AγT纯合体4例、杂合体12例;锡伯族中发现AγT杂合体6例。蒙古族中AγT基因频率(fAγT)为0.128,锡伯族为0.05。 Abstract: Gγ/Aγ、AγI/Aγ Ratios of fetal hemoglobin(HbF) in 138 cases of newborns of Megnol (n=78)and Sibo(n=60)ethnic groups in Urumuqi,Xinjiang were determined by HPLC.The means of % Gγ of Mongol and sibo ethnic groups were 73.99% and 7459% respectively.12 Aγ/T cases of heterozygotes in Mongol,6 in Sibo and 4 cases of AγT homozygotes in Mongol were found.The frequencies of AγT gene were 0.128 in Mongol and 0.05 in Sibo respectively.The means of AγT of Mongol and Sibo ethnic groups were 56.04% and 64.33% respectively.     

Inheritance and Expression of Copies of Transgenes 1Dx5 and 1Ax1 in Elite Wheat （Triticum aestivum L.） Varieties Transferred from Transgenic Wheat through Conventional Crossing

To study the inheritance and expression of multiple copies of transgenes from transgenic wheat lines, three crosses between transgenic wheat lines B72-8-11b and B102-1-2 and Chinese elite wheat varieties Chuan89-107 and Email 8 were carried out. Chuan89-107×B72-8-11b, Chuan89-107×B102-1-2 and Email 8×B72-8-11b, and F_1 plants were selfed or backcrossed to obtain different generation populations. Protein analysis in grains of F_1 and F_2 and backcross progenies of BC_1F_1, BC_1F_2, BC_1F_3, BC_2F_1, BC_2F_2 and BC_2F_3 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the transgenes lDx5 and lAx1 were expressed and segregated in the target wheat according to Mendelian laws. A range of lDx5 expression levels were observed in the progenies of Chuan89-107×B72-8-11b and Emai 18×B72-8-11b, but the expression levels of lAx1 in progenies of Chuan89-107×B102-1-2 rarely changed. It suggested that the two foreign genes had different mechanisms of expression in the cross progeny, even though they were produced in the same way and the foreign lDx5 gene of 5-10 copies had the more complicated expression mechanism than the lAx1 gene of 4-5 copies.     

Induction of HLA-G expression in a melanoma cell line OCM-1A following the treatment with 5-aza-2＇-deoxycytidine

The non-classical HLA class Ⅰ antigen HLA-G is an immune modulator which inhibits the functions of T cells, NK cells, and the Dendritic cells （DC）. As a result, HLA-G expression in malignant cells may provide them with a mechanism to escape the immune surveillance. In melanoma, HLA-G antigen expression has been found in 30% of surgically removed lesions but in less than 1% of established cell lines. One possible mechanism underlying the differential HLA-G expression in vivo and in vitro is that the HLA-G gene is epigenetically repressed in melanoma cells in vitro. To test this hypothesis, we treated the HLA-G negative melanoma cell line OCM-1A with the DNA methyltransferase inhibitor 5-aza-2＇-deoxycytidine （5-AC） and analyzed whether HLA-G expression can be restored. Our data strongly suggest that HLA-G is silenced as a result of CpG hypermethylation within a 5＇ regulatory region encompassing 220 bp upstream of the start codon. After treatment, HLA-G mRNA expression was dramatically increased. Western blot and flow cytometry showed that HLA-G protein was induced. Interestingly, HLA-G cell surface expression on the 5-AC treated OCM-1A cells is much less than that on the HLA-G positive JEG-3 cells while a similar amount of total HLA-G was observed. Possible mechanisms for the difference were analyzed in the study such as cell cold-treatment, peptide loading and antigen processing machinery components （APM） as well as β2 microglobulin （β2-m） expression. Data revealed that the APM component calreticulin might be involved in the lower HLA-G surface expression on OCM-1A cells. Taken together, our results indicated that DNA methylation is an important epigenetic mechanism by which HLA-G antigen expression is modulated in melanoma cells in vitro. Furthermore, to the first time, we hypothesized that the deficiency of calreticulin might be involved in the low HLA-G surface expression on the 5-AC treated OCM-1A cells.     

Fine-mapping of an Arabidopsis cell death mutation locus

An Arabidopsis cell death mutation locus was mapped to chromosome 2 between lGS1 and mi421. The YAC clone ends, CIC9A3R, CIC11C7L, CIC2G5R and RFLP marker CDs3 within this interval, were used to probe TAMU BAC library and 31 BAC clones were obtained. A BAC contig encompassing the mutation locus, which consists of T6P5, T7M23, T12A21, T8L6 and T18A18, was identified by Southern hybridization with the BAC ends as probes. 11 CAPS and 12 STS markers were developed in this region. These results will facilitate map-based cloning of the genes and sequencing of the genomic DNA in this region.     

The common MTHFR C677T and A1298C variants are not associated with the risk of non-syndromic cleft lip/palate in northern Venezuela

Non-syndromic cleft lip with or without cleft palate （nsCL/P） is among the most common major birth defects, with complex inheritance involving multiple genes and environmental factors. Numerous studies of MTHFR, encoding methylenetetrahydrofolate reductase, which catalyzes the rate-limiting step of folic acid biosynthesis, have shown inconsistent association of two common hypomorphic allelic variants, C677T and A1298C, in nsCL/P patients and, in some cases, their mothers. We have studied the MTHFR C677T and A1298C polymorphisms in nsCL/P patients, their mothers, and population-matched controls from northern Venezuela. We found no evidence for contribution of the MTHFR C677T and A1298C variants to the risk of nsCL/P in northern Venezuela. Overall, our findings fail to support a causal role of either the MTHFR C677T or A 1298C variants in the pathogenesis of nsCL/P in northern Venezuela.     

光合作用对胞间和大气CO_2响应曲线的比较

利用Li-6400便携式光合作用系统测定华北平原冬小麦在温度为25℃和30℃、光合有效辐射为1500和2000 mmol·m~(-2)·s~(-1)条件下处于抽穗时期旗叶的CO_2响应曲线,研究植物光合作用对胞间CO_2响应(A/C_i)和对大气CO_2响应(A/C_a)的直角双曲线修正模型所给拟合结果的合理性.结果表明:由A/C_i和A/C_a修正模型所给的光合能力和CO_2补偿点几乎相同,但得到的光呼吸速率和初始羧化效率则完全不等;产生这种差异的原因是利用叶片气体交换测定的数据所计算的胞间CO_2浓度并不是植物叶片本身的胞间CO_2浓度;A/C_a修正模型比A/C_i修正模型更为合理是因为A/C_a所估算的光呼吸速率接近测量值.

Abstract：

By using Li-6400 portable photosynthesis system, the photosynthetic parameters of winter wheat (Triticum aestivum) during its heading stage in North China Plain were measured at air temperature 25℃ and 30℃ and at photosynthetically available radiation 1500 and 2000 mmol·m~(-2)·s~(-1). The measured data were fitted with the modified rectangular hyperbola models of the photosynthetic responses to flag leaf intercellular CO_2 concentration (A/C_i) and air CO_2 concentration (A/C_a), aimed to approach the reasonability of the fitted results obtained from the models. The photosynthetic capacity and CO_2 compensation point estimated by the modified A/C_i curve and A/C_a curve were nearly the same, but the photorespiration and initial earboxylation ef-ficiency estimated by them were completely different. The difference between the two modified curves came from the calculated but not the real intercellular CO_2 concentration. Modified A/C_a curve was more reasonable than the modified A/C_i curve, because the photorespiration rate esti-mated by the former was close to the measured value.     

Ca^2＋-Calmodulin is Involved in Betacyanin Accumulation Induced by Dark in C3 Halophyte Suaeda salsa

The C3 halophyte Suaeda salsa was used to investigate the roles of Ca^2＋, Ca^2＋ channels, and calmodulin （CAM） in betacyanin metabolism. Seeds of S. salsa were cultured in both the dark and light for 3 days. The fresh weight and betacyanin content were much higher in S. salsa seedlings formed in the dark than in seedlings formed in the light. The addition of Ca^2＋ to the half-strength MS nutrient solution promoted betacyanin accumulation in the dark, whereas Ca^2＋ depletion by EGTA suppressed the dark-induced betacyanin accumulation in shoots of S. salsa. The Ca^2＋ channel blocker LaCl3 also inhibited dark-induced betacyanin accumulation. The highest activity of CaM and the maximum betacyanin content decreased by 51% and 45%, respectively, in shoots of S. salsa seedlings treated with the potent CaM antagonist chlorpromazine in the dark. Furthermore, the other CaM antagonist N-（6-aminohexyl）-5-chloro-l-naphthalenesulfonamide （W-7） also inhibited the activity of CaM and dark-dependent betacyanin accumulation, whereas its less active structural analog N-（6-aminohexyl）- 1-naphthalenesulfonamide （W-5） had little effect on the responses to dark of S. salsa seedlings. These results suggest that Ca^2＋, Ca^2＋-regulated ion channels, and CaM play an important role in dark-induced betacyanin accumulation in the shoots of the C3 halophyte S. salsa.