普通小麦细胞质雄性不育系及其保持系线粒体DNA的RAPD分析

应用随机扩增多态ＤＮＡ（ＲａｎｄｏｍａｍｐｌｉｆｉｅｄｐｏｌｙｍｏｒｐｈｉｃＤＮＡｓ,ＲＡＰＤ）技术,对普通小麦细胞质雄性不育系（Ａ）及其保持系（Ｂ）线粒体基因组（ｍｉｔｏｃｈｏｎｄｒｉａｌｇｅｎｏｍｅ）的指纹图谱进行了分析。共使用引物４１个,其中２０个引物得到了扩增产物,部分引物扩增结果表现多态性。说明线粒体ＤＮＡ（ｍｉｔｏｃｈｏｎｄｒｉａｌＤＮＡ,ｍｔＤＮＡ）序列在不育系和保持系之间存在差异,进一步明确了小麦细胞质雄性不育（ｃｙｔｏｐｌａｓｍｉｃｍａｌｅｓｔｅｒｉｌｅ,ＣＭＳ）与ｍｔＤＮＡ的关系。     

普通小麦细胞质雄性不育系及其保持系线粒体DNA和RAPD分析

应用随机扩增多态ＤＮＡ（Ｒａｎｄｏｍ ａｍｐｌｉｆｉｅｄ ｐｏｌｙｍｏｒｐｈｉｃ ＤＮＡｓ,ＲＡＰＤ）技术,对普通小麦细胞质雄性不育系（Ａ）及其保持系（Ｂ）线粒体基因组（ｍｉｔｏｃｈｏｎｄｒｉａｌ ｇｅｎｏｍｅ）的指纹图谱进行了分析。共使用引物４１个,其中２０个引物得到了扩增产物,部分引物扩增结果表现多态性。说明线粒体ＤＮＡ（ｍｉｔｏｃｈｏｎｄｒｉａｌ ＤＡＮ,ｍｔ,ＤＮＡ）序列在不育系和保持系之     

犬细小病毒中国内蒙株VP2基因克隆及序列分析

从我国内蒙古地区流行的犬细小病毒病病犬的肠溶物中分离提纯犬细小病毒（ＣＰＶ）。提取病毒基因组ＤＮＡ,并以此ＤＮＡ为模板,采用人工合成的引物进行ＰＣＲ扩增,ＰＣＲ产物经ＢａｍＨＩ、ＳａｃＩ双酶切后,克隆于ｐＵＣ１９质粒的ＢａｍＨＩ／ＳａｃＩ位点。重组质粒ｐＵＣＶＰ２经ＰＣＲ鉴定、限制酶切分析和序列分析,结果表明：获得了犬细小病毒内蒙株（ＣＰＶ－ＩＭ）ＶＰ２基因的全长克隆,ＶＰ２基因全长１７５５ｎｔ,     

抗原捕获聚合酶链式反应（AC－PCR）直接分型检测单纯疱疹病毒

用抗单纯疱疹病毒（ＨＳＶ）型共同性ｇＣ和ｇＤ羊克隆抗体（ＭｃＡｂ）,包被即Ｅｐｐｅｎｄｏｒｆ管,捕捉ＨＳＶ,同时加入３个引物：一个是ＨＳＶ─１／ＨＳＶ─２型共同性上游引物,另两个分别是ＨＳＶ─１和ＨＳＶ─２型特异性下游引物。借此建立了能直接分型检测ＨＳＶ的抗原捕获聚合酶链式反应（ＡＣ─ＰＣＲ）。ＨＳＶ─１的扩增产物为４７７ｂｐ,ＨＳＶ─２的为３９９ｂｐ两型病毒经ＡＣ─ＰＣＲ扩增后产生分子量不同的ＤＮＡ片段,致使ＡＣ─ＰＣＲ能直接分型检测ＨＳＶ。ＨＳＶ─１和ＨＳＶ─２扩增产物的克隆和序列分析表明,本方法特异性好。用本法检测Ｂａｌｂ／ｃ幼鼠中枢神经系统ＨＳＶ感染的脑标本,进一步证实本方法不仅敏感、特异,而且分型准确。     

BRCA1基因结构及其在乳腺癌中的表达

利用ＭＰＣＲ技术从乳腺组织分离到抑癌基因ＢＲＣＡ１的ｃＤＮＡ片段,将此９１４ｂｐ的片段克隆进质粒ｐＵＣ１１８,并经全序列测定证实。序列分析表明,ＢＲＣＡＩｃＤＮＡ编码的肽链ＮＮ２－末端有一锌指结构,抑癌基因ＢＲＣＡＩ的产物可能是ＤＮＡ结合蛋白,ｃＤＮＡ序列存在两个变异位点：一个是第４０９位的Ｃ→Ａ（Ａｓｐ→Ｇｌｕ）：另一个是第８７９位的Ａ→Ｔ（ＭＩａ同义突变）。以该片段为探针,检测６例乳腺癌组织中ＢＲＣＡＩｍＩＭＡ表达,一例表达明显下降,一例没检测到表达的ｍＩＭＡ产物,说明一些乳腺癌组织的ＢＲＣＡ１基因转录水平降低     

甜菜多粘菌基因组片段的克隆4及PCR检测

根据资料报导设计引物，扩增Ｐｏｌｙｍｙｘａ ｂｅｔａｅ的基因组片段，钭其克隆在ＰＧＥＭ－３Ｚｆ（＋）质粒载体上，并通过双酶切、ＰＣＲ扩增和部分序列测定，证明克隆片段为Ｐ．ｂｅｔａｅ基因组片段。用扩增Ｐ．ｂｅｔａｅ基因组片段的引物 Ｐ．ｇｒａｍｉｎｉｓ侵染小麦和Ｏ．ｔｒａｓｓｉｃａｅ侵染豇豆根系抽提的总ＤＮＡ进行ＰＣＲ扩增，均未获得任何ＤＮＡ产物，进一步证实了上述结果。对移人病士２、３．５天的甜菜苗     

利用PCR技术行反义寡核苷酸体外抗丁型肝炎病毒基因组RNA中核酶的研究

设计一对ＰＣＲ引物,其中上游引物的５’端除目的基因外,还加Ｔ７ＲＮＡ聚合酶启动子序列,以质粒（ｐＳＶＬＤ３）为模板,通过ＰＣＲ扩增出带有Ｔ７ＲＮＡ聚合酶启动子序列的１３９ｂｐ的ｃＤＮＡ片段,它含有丁型肝炎病毒（ＨＤＶ）基因组ＲＮＡ中核酶（Ｒｉｂｏｚｙｍｅ）区的ｃＤＮＡ该核酶具有自身裂解功能,经测序发现该ｃＤＮＡ有２个碱基变异,以此ＰＣＲ产物为模板,通过Ｔ７ＲＮＡ聚合酶,转录出核酶的前体,并观察到其     

水稻线粒体DNA雄性不育有关特异片段的克隆及序列分析

应用任意单引物聚合酶链反应技术,从水稻ＷＡ 型雄性不育系的线粒体ＤＮＡ 中得到一个特异的扩增片段Ｒ２－６３０ ＷＡ。以该片段为探针进行Ｓｏｕｔｈｅｒｎ 杂交分析检测到在雄性不育胞质与正常可育胞质间存在的线粒体ＤＮＡ 多态性。不育系珍汕９７Ａ 和其Ｆ１ 杂种的杂交图谱相同。而保持系珍汕９７Ｂ和恢复系明恢６３ 的杂交图谱一样。序列测定该片段全长６２９ ｂｐ,其碱基组成Ａ＋ Ｔ＝ ５４．１％ ,同源性比较结果显示, 该片段与１２３６ 个已报道的植物基因（包括１６ 个水稻线粒体基因）序列的同源性均小于５０％ 。序列内含有一个长度为１０ ｂｐ 的反向重复序列５－ＡＣＣＡＴＡＴＧＧＴ－３,位于２６２—２７２ 区段。另外,其３７９—４３９ 区段可编码一个含２０个氨基酸残基的短肽。上述结果表明,Ｒ２－６３０ ＷＡ 片段确与水稻野败型雄性不育密切相关。推测反向重复序列５－ＡＣＣＡＴＡＴＧＧＴ－３在细胞质雄性不育性状形成中,可能起着重要作用     

国内信息

ＤＥＧＣＭ技术中的ＲＤＡ、ＳＳＨ和ＲＳＤＤ差异表达基因分离技术 (ＤＥＧＣＭ )发展很快 ,主要是ＰＣＲ技术的发展和相应新技术的出现为ＤＥＧＣＭ注入了新的活力。ＰＣＲ引入差式筛选之中 ,可提高效力和降低假阳性率。若引入扣除杂交 ,可发展扣除扩增方案 ,并用特异引物结合于ＰＣＲ中选择扩增差异ｃＤＮＡ而形成代表性差式分析法 (ＲＤＡ)。采用抑制性ＰＣＲ选择性扩增差异基因片段 ,用ＤＮＡ链内“退火”优先于链间退火 ,使非目的序列产生“发夹”式互补结构 ,不能与引物配对 ,从而选择性抑制非目的基因片段的扩增 ,以此形成抑制性差…     

中国棉铃虫P450家族的CYP6B2基因与抗药性关系

运用ＲＴ－ＰＣＲ技术从棉铃虫五龄幼虫扩增到一个６２７ｂｐ的ＤＮＡ片段,测序表明这一片段为ＣＹＰ６Ｂ２基因的功能保守区,以这一片段为探针对棉铃虫除除虫菊酯抗性（Ｒ）及敏感（Ｓ）品系的总ＲＮＡ进行点杂交。ＲＮＡ点杂交表明未经氰戊菊酯诱导的情况下Ｒ品系的ＣＹＰ６Ｂ２基因的ｍＲＮＡ水平明显高于Ｓ品系,即为转录水平的调控,而经氰戊菊酯诱导后杂交表明Ｓ品系明显０被氰戊菊酯诱导,但Ｒ品系不被诱导。由此推测,棉铃     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.