蓝氏贾第鞭毛虫细胞骨架蛋白的分子生物学研究进展

蓝氏贾第鞭毛虫作为真核生物的模型,越来越受到广大生物学学者的重视,贾第虫借助细胞骨架蛋白附着于宿主肠上皮细胞,导致贾第虫病。将蓝氏贾第鞭毛虫细胞骨架蛋白成分作为新药物开发靶点的研究与日俱增。本文综述了蓝氏贾第鞭毛虫细胞骨架蛋白的分子生物学研究方法及最新进展,为新药物的开发及贾第虫骨架蛋白的进一步研究提供有价值的资料。     

基于磷酸丙糖异构酶基因序列的蓝氏贾第鞭毛虫分子系统发育的研究

[目的 ]探讨蓝氏贾第鞭毛虫种内系统发育及遗传多样性。 [方法 ]对不同来源虫株的磷酸丙糖异构酶(tim)基因进行 PCR扩增、序列测定后 ,用简约法和 NJ法构建分子系统树进行系统学分析。 [结果 ]在所测序列中共有 12 4个位点存在变异 (2 3% ) ,且大多数为发生在第三密码子的同义突变 ,两种构树方法所得两树的分枝结构相似 ,均将受试的 16株蓝氏贾第鞭毛虫分为明显的两组。 [结论 ]tim基因可作为研究蓝氏贾第鞭毛虫群体遗传结构一个有效的遗传标记     

多位点基因分型用于蓝氏贾第鞭毛虫遗传多样性的研究进展

蓝氏贾第鞭毛虫(简称贾第虫)是一种重要的人兽共患肠道原虫,宿主广泛。目前,种内有8个有效聚集体型。随着分子生物学技术的发展,多位点基因分型(multi-locus genotyping,MLG)技术被广泛用于贾第虫的研究。该文就MLG技术在阐述贾第虫遗传多样性、评估人兽共患传播的可能性及分类学上的应用研究作一综述。     

C2株蓝氏贾第鞭毛虫组蛋白H2B基因的克隆与同源性分析

目的 获取C2株蓝氏贾第鞭毛虫H2B组蛋白基因序列,与WB株蓝氏贾第鞭毛虫及其他物种进行同源分析。方法 PCR扩增获取H2B组蛋白基因,连接pGM-T载体,转化E. coli DH5α感受态宿主细胞,挑选阳性克隆并进行序列分析,与美国WB株蓝氏贾第鞭毛虫及模式生物H2B组蛋白基因和蛋白序列进行同源分析。结果 测序C2株蓝氏贾第鞭毛虫H2B组蛋白基因序列,同源比对结果显示其基因序列与美国WB株完全一致,进化树分析表明贾第虫H2B组蛋白基因在进化过程中与其他物种分化较早。结论 蓝氏贾第鞭毛虫H2B组蛋白基因同源分析结果显示贾第虫与其他现存真核生物亲缘关系较为疏远,为进一步研究蓝氏贾第鞭毛虫的生物进化地位提供有价值的资料。     

C2株蓝氏贾第鞭毛虫组蛋白H3基因的克隆表达与基因分析

目的 克隆表达C2株蓝氏贾第鞭毛虫H3组蛋白基因,与WB株蓝氏贾第鞭毛虫进行同源分析,构建C2株蓝氏贾第鞭毛虫H3组蛋白分子进化树。方法 PCR扩增获取H3组蛋白基因,构建pGM-T-H3重组载体,转化E. coli TOP10感受态宿主细胞,挑选阳性克隆并进行序列分析,利用限制性内切酶NcoⅠ和 XhoⅠ构建pET28a(+)-H3重组载体,转化E. coli Rosetta( DE3),IPTG诱导组蛋白H3表达,Western blotting鉴定表达,与美国WB株蓝氏贾第鞭毛虫及模式生物H3组蛋白基因和蛋白序列进行同源分析。结果 成功克隆表达C2株蓝氏贾第鞭毛虫H3组蛋白基因,同源比对结果显示C2株蓝氏贾第鞭毛虫基因序列与美国WB株完全一致,但与其他现存真核生物亲缘关系较为疏远。结论 C2株蓝氏贾第鞭毛虫H3组蛋白分子进化树分析表明贾第虫H3组蛋白基因在进化过程中与其他物种分化较早,本研究结果为进一步研究蓝氏贾第鞭毛虫的生物进化地位提供有价值的实验资料。     

隐孢子虫和蓝氏贾第鞭毛虫分子流行病学研究进展

宿主被隐孢子虫和蓝氏贾第鞭毛虫(简称贾第虫)感染后会出现腹泻等健康问题,严重时可致死亡。隐孢子虫病和贾第虫病均属于新发传染病,其疾病负担往往被低估,是被忽视的重要公共卫生问题。分子生物学技术在隐孢子虫和贾第虫的检测、基因分型及溯源等方面发挥着重要作用。本文就隐孢子虫和贾第虫的分子流行病学进展作一综述,为其防控提供依据。     

基于TPI基因的城市污水中蓝氏贾第鞭毛虫的分子鉴定

目的对哈尔滨市污水处理厂原水中的蓝氏贾第鞭毛虫进行分子鉴定。方法收集哈尔滨市污水处理厂原水样,提取基因组DNA,巢式PCR扩增蓝氏贾第鞭毛虫TPI基因,通过序列分析确定蓝氏贾第鞭毛虫的集聚体类型和亚型,并进行同源性分析。结果从哈尔滨市污水处理厂原水DNA提取物中扩增出蓝氏贾第鞭毛虫TPI基因,经分子鉴定为蓝氏贾第鞭毛虫集聚体AII,其序列与文献报道人源蓝氏贾第鞭毛虫集聚体AII序列(AB516351,FJ560570,EF688021)的同源性为100%。结论哈尔滨市污水处理厂原水中存在蓝氏贾第鞭毛虫集聚体AII,威胁当地居民健康。     

环介导等温扩增技术检测蓝氏贾第鞭毛虫

目的 建立应用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)检测蓝氏贾第鞭毛虫的方法. 方法 体外培养蓝氏贾第鞭毛虫滋养体,提取DNA.根据GenBank显示的贾第虫序列及环介导等温扩增技术的原理,设计4条贾第虫特异引物,利用LAMP检测蓝氏贾第鞭毛虫DNA,以隐孢子虫卵囊DNA、疟原虫DNA为对照,并将不含病原体DNA的纯水作为阴性对照.LAMP产物经SYBR green I显色后观察结果,绿色为阳性,棕色为阴性;对LAMP产物进行琼脂糖凝胶电泳分析,观察其特征条带的情况. 结果 蓝氏贾第鞭毛虫DNA检测管经显色后呈绿色,隐孢子虫卵囊DNA、疟原虫DNA及水阴性对照管呈棕色.含有蓝氏贾第鞭毛虫DNA的LAMP产物经电泳后呈LAMP特征性梯状条带,安氏隐孢子虫DNA、恶性疟原虫DNA及阴性对照水无扩增产物. 结论 成功建立了检测蓝氏贾第鞭毛虫的LAMP方法.     

环介导等温扩增技术检测蓝氏贾第鞭毛虫

目的 建立应用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)检测蓝氏贾第鞭毛虫的方法. 方法 体外培养蓝氏贾第鞭毛虫滋养体,提取DNA.根据GenBank显示的贾第虫序列及环介导等温扩增技术的原理,设计4条贾第虫特异引物,利用LAMP检测蓝氏贾第鞭毛虫DNA,以隐孢子虫卵囊DNA、疟原虫DNA为对照,并将不含病原体DNA的纯水作为阴性对照.LAMP产物经SYBR green I显色后观察结果,绿色为阳性,棕色为阴性;对LAMP产物进行琼脂糖凝胶电泳分析,观察其特征条带的情况. 结果 蓝氏贾第鞭毛虫DNA检测管经显色后呈绿色,隐孢子虫卵囊DNA、疟原虫DNA及水阴性对照管呈棕色.含有蓝氏贾第鞭毛虫DNA的LAMP产物经电泳后呈LAMP特征性梯状条带,安氏隐孢子虫DNA、恶性疟原虫DNA及阴性对照水无扩增产物. 结论 成功建立了检测蓝氏贾第鞭毛虫的LAMP方法.     

环介导等温扩增技术检测蓝氏贾第鞭毛虫

目的 建立应用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)检测蓝氏贾第鞭毛虫的方法. 方法 体外培养蓝氏贾第鞭毛虫滋养体,提取DNA.根据GenBank显示的贾第虫序列及环介导等温扩增技术的原理,设计4条贾第虫特异引物,利用LAMP检测蓝氏贾第鞭毛虫DNA,以隐孢子虫卵囊DNA、疟原虫DNA为对照,并将不含病原体DNA的纯水作为阴性对照.LAMP产物经SYBR green I显色后观察结果,绿色为阳性,棕色为阴性;对LAMP产物进行琼脂糖凝胶电泳分析,观察其特征条带的情况. 结果 蓝氏贾第鞭毛虫DNA检测管经显色后呈绿色,隐孢子虫卵囊DNA、疟原虫DNA及水阴性对照管呈棕色.含有蓝氏贾第鞭毛虫DNA的LAMP产物经电泳后呈LAMP特征性梯状条带,安氏隐孢子虫DNA、恶性疟原虫DNA及阴性对照水无扩增产物. 结论 成功建立了检测蓝氏贾第鞭毛虫的LAMP方法.     

比较基因组学在蓝氏贾第鞭毛虫进化研究中的应用新进展

蓝氏贾第鞭毛虫(简称贾第虫)作为一种古老的真核生物,在生物进化过程中的地位举足轻重。比较基因组学能够在基因组水平上深入认识贾第虫的进化关系,进一步明确贾第虫在生物进化中的地位。本文对比较基因组学的主要研究方法进行综述,同时介绍比较基因组学在贾第虫生物进化研究中的应用,对贾第虫比较基因组学的发展进行展望。     

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.     

Sickle cell disease: a multigenic perspective of a single gene disorder

The phenotypic heterogeneity of sickle cell disease continues to puzzle clinicians and investigators more than half a century after the elucidation of its molecular basis. Although advances have been made in understanding the influences of globin gene-related factors such as alpha-thalassemia (thal) and high Hb F determinants, these are far from providing a satisfactory explanation to the variation and clinical diversity of sickle cell disease in many cases. The sequencing of the human genome and the development of novel technologies such as high throughput genotyping and analysis of gene expression through cDNA microarrays has made it possible to investigate this diversity with these approaches and identify novel genetic modifiers of sickle cell disease. This brief review focuses on the recent advances in our understanding of the impact of non globin genetic modifiers on the phenotypic diversity of the disease.     

蓝氏贾第鞭毛虫检测方法的研究进展

蓝氏贾第鞭毛虫是一种重要的水源性人兽共患的寄生原虫,可致人和动物的腹泻.传统的检测方法主要为粪便检查,随着免疫学与分子生物学技术的应用,其免疫学检测和分子生物学检测近年来有了较大的发展.该文就上述研究进展进行综述.     

蓝氏贾第鞭毛虫检测方法的研究进展

蓝氏贾第鞭毛虫是一种重要的水源性人兽共患的寄生原虫,可致人和动物的腹泻.传统的检测方法主要为粪便检查,随着免疫学与分子生物学技术的应用,其免疫学检测和分子生物学检测近年来有了较大的发展.该文就上述研究进展进行综述.     

Gut associated immune responses in clinical and experimental giardiasis: an overview

Giardia lamblia, the protozoan parasite, first described by Von Leewenhoek in 1681, has come into prominence in last quarter century because of mounting awareness that it may cause significant morbidity and loss of man power. Earlier thought to be a commensal organism, it has been recognised as a true intestinal pathogen in the past three decades. Nevertheless, the mechanism of the disease caused by this protozoan parasite (in the human host's small intestine) continues to remain unexplained. The infection with G. lamblia is worldwide with an average prevalence of 12.5 per cent and is especially common in children and may cause failure of child to thrive. The G. lamblia infection has been implicated in a number of water borne epidemics and is important cause of traveller's diarrhoea all over the world. Infection with G. lamblia may be entirely asymptomatic, may produce a mild, self limiting illness or chronic diarrhoea with or without malabsorption. The reasons for such variations in severity are not clearly understood. However, interplay of virulence of parasite, nutritional status and type of the host immune responses and its effect on intestinal mucosa appear to modulate the infection.     

Use of massively parallel pyrosequencing to evaluate the diversity of and selection on Plasmodium falciparum csp T-cell epitopes in Lilongwe, Malawi

The development of an effective malaria vaccine has been hampered by the genetic diversity of commonly used target antigens. This diversity has led to concerns about allele-specific immunity limiting the effectiveness of vaccines. Despite extensive genetic diversity of circumsporozoite protein (CS), the most successful malaria vaccine is RTS/S, a monovalent CS vaccine. By use of massively parallel pyrosequencing, we evaluated the diversity of CS haplotypes across the T-cell epitopes in parasites from Lilongwe, Malawi. We identified 57 unique parasite haplotypes from 100 participants. By use of ecological and molecular indexes of diversity, we saw no difference in the diversity of CS haplotypes between adults and children. We saw evidence of weak variant-specific selection within this region of CS, suggesting naturally acquired immunity does induce variant-specific selection on CS. Therefore, the impact of CS vaccines on variant frequencies with widespread implementation of vaccination requires further study.