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载脂蛋白E(apolipoproteinE ,apoE)由 2 99个氨基酸组成 ,分子量 34kD ,是维持人体正常脂质代谢的必需蛋白质 .它是乳糜微粒 (CM )、极低密度脂蛋白 (VLDL)和高密度脂蛋白 (HDL)的组分 ,是极低密度脂蛋白受体的重要配体 ,是脂质进入细胞不可缺少的中介 .apoE有 3种同分异构体 :apoE2、apoE3、apoE4 ,分别具有不同的生理作用 .apoE4与血浆高胆固醇、心血管疾病和老年痴呆等疾病关联[1~ 3 ] .apoE2与Ⅲ型高脂血症有关 ,并对老年痴呆有防治作用[4,5] .apoE3是大多数健康人所具有… 相似文献
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中国东北汉族及3个少数民族DYS19和DYS287多态性研究 总被引:6,自引:0,他引:6
本文以中国东北汉族和鄂温克,鄂伦春,达斡尔3个少数民族人群为研究对象,采用PCR产物变性聚丙烯酰胺凝胶电胶的方法分析了Y染色体特异性微卫星DYS19的等位基因分布规律。结果显示:东北汉族人群中各等位基因分布较分数A2.9%,B26.09%,C26.09%,D28.98%,E15.94%;东北汉族和3个少数民族人群的等位基因频率有显著性差异。 相似文献
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MTHFR基因多态性与动脉粥样硬化性脑梗塞的关系 总被引:8,自引:0,他引:8
采用PCR- RFLP技术,检测了62 例动脉粥样硬化性脑梗塞患者和79 名对照者的C677T 突变的基因型。结果发现, MTHFR基因C677T 突变型等位基因(V)频率在实验组和对照组中,有显著性差异(χ2= 4.41,P< 0.05);三种基因型频率在两组人群中均无显著性差异。基因型频率的相对风险分析,AV基因型比AA 基因型患脑梗塞风险高1.76 倍;VV 基因型比AA 基因型患脑梗塞风险高3.25 倍。结果表明, MTHFR 基因C677T 突变型等位基因与动脉粥样硬化性脑梗塞有一定的关联,突变基因型增加了动脉粥样硬化脑梗塞的发病风险。 相似文献
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人突变appE基因在转基因鼠体内的表达及血清脂质变化 总被引:3,自引:0,他引:3
为了研究人突变apoE7基因在血脂代谢中的作用.采用微注射的方法建立了人apoE7转基因鼠,三个首建鼠(tg1,tg2,tg3)整合目的基因的拷贝数相差2倍左右,其血中表达的人apoE7的水平也不相同,低水平表达的tg1为1.26mg/dl,高水平表达的首建鼠tg3血清中apoE7浓度可高达21.1mg/dl.异常apoE基因的表达导致了转基因鼠血清甘油三酯和胆固醇明显升高,为对照的1.5~3倍.高密度脂蛋白HDL降低,低密度脂蛋白LDL和极低密度脂蛋白VLDL升高.经20mmol/LZnSO4诱导后,F1代Tg3鼠系血清甘油三酯(TG)水平高达444mg/dl,胆固醇(TC)高达234mg/d1.HDL升高和LDL/VLDL降低十分明显,表现了高脂血症的指征. 相似文献
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微卫星位点DYS19在中国人群的多态研究 总被引:6,自引:0,他引:6
以人DNA为模板,经PCR扩增后,用聚丙烯酰胺胶电泳分离扩增片段,再经高灵敏度银染着色,对中国陕西汉族、广东汉族、宁夏回族、辽宁满族、四川彝族。西藏藏族。广西壮族、广西瑶族。新疆维吾尔族、湖南土家族等10个人群535名个体的Y染色微卫星位点因,基因频率范围在0.25-0.61;等位基因B、D次之,基因频率范围分别为0.080.36、0.06-0.42;而等位基因A和E频率较低,频率范围分别为0-0 相似文献
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利用生化及分子标记确定长穗偃麦草(Elytrigia elongatum,EE.2n=14) … 总被引:1,自引:0,他引:1
利用限制性片段长度多态性(RFLP)及等电聚焦(IEF)技术确定普通小麦中国春-二倍体长穗偃麦草7个异附加系所附加的外源染以体与小麦染色体的部分同源性,共有8个生化标记,13个RFLP标记在亲本间揭示了多态性,结果表明:长穗偃麦草的1E,2E,3E,4E,5E,6E,7E7条染色体分别与小麦染色体的1、2、3、4、5、6、77个部分同源群具有部分同源关系,偃麦草的1E与7E、5E与7E染色体间可能 相似文献
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植物抗寒剂CR-4在我区水稻育秧中的应用效果张鹏至,田博荣(天津市东丽区农业技术中心,天津市300300)APPLICATIONEFFECTSOFTHEPLANTCOLD-RESISTERCR-4FORRICESEEDLINGCULTUREINOUR... 相似文献
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植物抗寒剂CR-4在湖南水稻生产中的应用效果段传嘉(湖南省水稻研究所,长沙410125)APPLICATIONEFFECFSOFTHECOLD-RESISTERCR-4INRICECULTUREOFHUNANPROVINCE¥Duanchuan-ji... 相似文献
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利用生化及分子标记确定长穗偃麦草(Elytrigia elongatum, EE. 2n=14)染色体与小麦染色体的部分同源性 总被引:2,自引:1,他引:1
利用限制性片段长度多态性(RFLP)及等电聚焦(IEF)技术确定普通小麦中国春-二倍体长穗僵麦草7个异附加系所附加的外源染色体与小麦染色体的部分同源性,共有8个生化标记,13个RFLP标记在亲本间揭示了多态性。结果表明:长穗堰麦草的IE、2E、3E、4E、 5E、6E、7E 7条染色体分别与小麦染色体的 1、2、3、4、5、6、7 7个部分同源群具有部分同源关系,堰麦草的IE与7E、5E与7E染色体间可能发生过重排。同时,研究还分别将Est-E5、Est-E8位点定位于3EL,Per-E1定位于7E, Per-E4定位于5E,β-Amy-E1定位于4EL染色体,并进一步将α-Amy-E1位点定位于6E染色体长臂上。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献