斜纹夜蛾核型多角体病毒p74基因的克隆和序列分析

用ＡｃＮＰＶｐ７４基因３’端的１．４ｋｂ片段,通过Ｓｏｕｔｈｅｒｎｂｌｏｔｔｉｎｇ将ＳｐｌｔＮＰＶ的ｐ７４基因定位于ＸｈｏＩ（４．９ｋｂ）、ＥｃｏＲＩ（４．４ｋｂ）、ＢａｍＨＩ（３．０ｋｂ）片段上。进一步用ＥｘｏⅢ和构建亚克隆测序法,对长２５４５ｂｐ的ｐ７４基因进行,其中１９７４ｂｐ的编码编码６５８个氨基酸,蛋白分子量约７５．８７ｋＤ,其编码蛋白与ＡｃＭＮＰＶ和ＣｆＭＮＰＶｐ７４蛋白的氨基酸序列同     

用PCR扩增和克隆马立克氏病病毒糖蛋白D基因

用ＰＣＲ技术,从ＧＡ株马立克氏病病毒（ＭＤＶ）感染的成纤维细胞（ＧＥＦ）基因组ＤＮＡ中扩增出ＭＤＶ糖蛋白Ｄ（ｇＤ）抗原基因片段的约１３００ｂｐ编码序列,将该ｐｃＲ扩增的产物于ＥｃｏＲＩ和Ｋｐｎｌ位点克隆到ｐＵＣ１８质粒载体中,在以ｄｉｇｏｘｉｇｅｎｉｎ（ｄｉｇ）标记的ｇＤＰＣＲ产物作为探针,进行原位杂交初步筛选到阳性重组质粒克隆,再根据酶切分析筛选到含ＭＤＶｇＤ基因的重组质粒ｐ１８ＭｇＤ。将ｐ１８ＭｇＤ质粒ＤＮＡ用ｄｉｇ标记后,在Ｓｏｕｔｈｅｒｎｂｌｏｔ中,该探针能识别ＭＤＶ基因组ＤＮＡ的ＢａｍＨＩ－Ａ克隆中的Ａ片段ＤＮＡ。酶切位点分析表明,该ｇＤ克隆也和已发表的ＭＤＶ的ＲＢＩＢ株ｇＤ一样,不含有ＥｃｏＲⅠ、ＨｉｎｄⅢ、ＰｓｔⅠ、ＳｍａⅠ、ｐｖｕⅡ等酶切位点。证明该重组质粒是ＭＤＶｇＤ克隆。     

麦迪霉素4″—O—丙酰基转移酶（mpt）基因结构的研究

对含有麦迪霉素４″－Ｏ－丙酰基转移酶（ｍｐｔ）基因的ＢａｍＨＩ－ＢａｍＨＩ８．０ｋｂ的ＤＮＡ片段进行限制性酶切分析,绘制出了含有２１个酶切位点的限制性酶切图谱。以含有碳霉素异戊酰基转移酶基因（ＣａｒＥ）的２．４ｋｂ ＤＮＡ片段为探针,经Ｓｏｕｔｈｅｒｎ ｂｌｏｔ分子杂交,将ｍｐｔ定位于一个ＥｃｏＲＩ－ＥｃｏＲＩ－ＰｓｔＩ３．０ｋｂ的ＤＮＡ片段上,将该片段克隆至大肠杆菌／链霉菌穿梭质粒载体ｐＷＨＭ３     

中国野生葡萄葛蘲叶绿体DNA质粒文库的构建

限制性内切酶ＢａｍＨＩ水解中国野生葡萄葛（ＶｉｔｉｓｆｌｅｘｕｏｓａＴｈｕｎｂ）的叶绿体ＤＮＡ（ｃｐＤＮＡ）,电泳分离为３４条带,最大为１１．７ｋｂ,最小为０．２３ｋｂ,分别用ｐＵＣ和ｐＢＲ３２２质粒克隆所得片段,转化大肠杆菌,并从转化菌中提取质粒ＤＮＡ,经酶切电泳分析证明含有葛ｃｐＤＮＡ经ＢａｍＨＩ水解的不同片段,从而构建了葛ｃｐＤＮＡ的ＢａｍＨＩ质粒文库。     

人巨细胞病毒的分子克隆及其特异性DNA探针的制备

从人巨细胞病毒（ＨＣＭＶ）培养物中提取ＨＣＭＶ并抽提其ＤＮＡ,经限制性内切酶ＢａｍＨＩ完全消化后,与质粒ｐＢｌｕｅｓｃｒｉｐｔ－ＳＫ重组建立了ＨＣＭＶ的ＤＮＡ文库,从此文库。中随机筛选出两个重组质粒（ｐＣＭＶ－１和ｐＣＭＶ－２）,用ＢａｍＨＩ分析证明其中所含的病毒ＤＮＡ片段的大小分别为１．０ｋｂ和７．５ｋｂ,将这两种质粒大量扩增纯化后,用光生物素进行标记作为探针,证明其只与ＨＣＭＶ反应,与正常人细胞ＤＮＡ及Ⅰ型和Ⅱ型单纯疤疹病毒ＤＮＡ无交叉反应。     

绿色木霉纤维素酶CBHⅡ基因的结构研究

实验经限制性酶切和双向Ｓｏｕｔｈｅｒｎ杂交将重组质粒ｐＣＢＨＩＩ－１４的１４ｋｂ外源片段上的绿色木霉纤维素酶ＣＢＨＩＩ基因定位于４．４ｋｂ的ＥｃｏＲＩ片段上,将该片段克隆于质粒ｐＵＣ１９,获得重组质粒ｐＣＢＨＩＩ。通过限制性分析构建了ｐＣＢＨＩＩ上４．４ｋｂＥｃｏＲＩ片段的物理图谱。在此基础上用质粒制作该片段的亚克隆,采用Ｓａｎｇｅｒ双脱氧链终止法测定了含绿色木霉纤维素酶ＣＢＨＩＩ基因的４０７４ｂｐ的ＤＮＡ序列,由ＧＴ－ＡＧ规则和ｃＤＮＡ序列推知该结构基因由４个外显子和３个内含子组成,总长１６１３ｂｐ,５′端存在与一般真核基因类似的两个特征性调控序列,但３′端不存在真核基因通常具有的特征序列而存在功能未明的短重复序列和嘧啶富集区。并对纤维素酶基因间的同源性和可能的功能作了初步的探讨。     

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,     

马立克氏病病毒（MDV）814株B抗原基因的克隆及部分序列分析

提取感染鸡胚成纤维细胞ＭＤＶ－Ｉ弱毒株８１４病毒ＤＮＡ为模板,根据ＲＢＩＢ株ｇＢ基因５′及３′两端核苷酸离列设计引物,利用ＰＣＲ技术扩增了我国ＭＤＶ－Ｉ弱毒株８１４ｇＢ基因（２．９ｋｂ）将扩增片段平末端克隆到载体ｐＢｌｕｅｓｃｒｉｐｔＳＫ中ＥｃｏＲＶ位点,经ＢａｍＨＩ,ＨｉｎｄＩＩＩ酶切鉴定得到不同插入方向的重组质粒。构建圹增片段的酶切图谱及部分序列分析证明与ＲＢＩＢ株ｇＢ基因无差异,显示了极高的     

中国野生葡萄葛lei叶绿体DNA质粒文库的构建

限制性内切酶ＢａｍＨＩ水解中国野生葡萄葛ｌｅｉ的叶绿体ＤＮＡ（ｃｐＤＮＡ）,电泳分离为３４条带,最大为１１．７ｋｂ,最小为０．２３ｋｂ,分别为ｐＵＣ和ｐＢＲ３２２质粒克隆所得片段,转化大肠杆菌,并从转化菌中提取质粒ＤＮＡ,经酶切电泳分析证明含有葛ｌｅｉ ｃｐＤＮＡ经ＢａｍＨＩ水解的不同片段,从而构建了葛ｌｅｉ ｃｐＤＮＡ的ＢａｍＨＩ质粒文库。     

利用Tn5gusA5对大豆慢生根瘤菌lrp基因的诱变

通过对重组质粒ｐＧＸＮ３００中的 ２．３ｋｂ ＥｃｏＲＩ片段测序分析发现,其上有一完整的ｌｒｐ基因和部分 ｐｕｔＡ基因,与 Ｋｉｎｇ ＮＤ等［１］报道的 Ｂ．ｊａｐｏｎｉｃｕｍ的ｌｒｐ基因ＤＮＡ序列有 ８８％同源性。利用 Ｔｎ５ ｇｕｓＡ５定位 诱变方法,对质粒ｐＧＸＮ３００进行插入诱变,得到２．３ｋｂ　ＥｃｏＲＩ片段上有Ｔｎ５ｇｕｓＡ５插入位点的质粒ｐＧＸＮ３００－ Ｔ３８,将ｐＧＸＮ３００－Ｔ３８转移到大豆馒生根瘤苗（Ｂ．ｊａｐｏｎｉｃｕｍ）ＧＸ２０１中,得到的ＧＸ２０１转移接合子与不相容 质粒ｐＰＨ１ＪＩ发生同源双交换。通过抗性及ｇｕｓＡ活性检测,筛选到一ｌｒｐ基因突变株。Ｓｏｕｔｈｅｍ杂交分析证 明这突变株的 Ｔｎ５ ｇｕｓＡ５插入确实是同源交换而不是转座产生,表明 Ｔｎ５ ｇｕｓＡ５ 诱变可以应用于大豆慢生根 瘤菌中的突变林筛选。     

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.     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.