粘类小麦细胞质雄性不育系的RAPD分析

利用250条10-聚寡核苷酸随机引物对具粘果山羊草(Aegilops kotschyi)、易变山羊草(Ae.variabilis)、偏凸山羊草(Ae.ventricosa)和二角山羊草(Ae．bicornis)细胞质不育系及其保持系5-1的总DNA进行了RAPD多态性分析,其中31条引物对4种不育系及其保持系总DNA均无扩增,217条引物扩增条带完全相同。有2条随机引物在2种不育系之间有特异的扩增片段,其中引物S22在偏凸山羊草细胞质雄性不育系基因组DNA中扩增出分子量约为1600bp的特异带,引物S202在粘果山羊草细胞质雄性不育系基因组DNA中扩增出约1300bp特异带。线粒体基因组DNA的RAPD分析表明,4种不育系及其保持系mtDNA存在明显的差异。证明了S22—1600为偏凸山羊草细胞质不育系及其mtDNA基因组DNA的RAPD特异片段．S202—1300可能为粘果山羊草细胞质不育系及其ctDNA基因组DNA的RAPD特异片段。     

花椰菜细胞质雄性不育系及保持系中特异序列的克隆、分析

以细胞质雄性不育花椰菜ogura-A和相应的保持系ogura-B为材料进行ISSR及DDRTPCR分析.选用30条ISSR引物,经扩增共产生306条清晰可辨的条带.每条引物可产生6-12条带,其中引物ISSR3在两系中呈现多态性扩增,在保持系中特异扩增出一条1100 bp的片段,序列分析表明该片段与油菜、拟南芥线粒体基因组的部分序列高度相似.推测其可能来源于花椰菜线粒体基因组.在DDRT-PCR分析中,选用3条锚定引物、15条随机引物进行组合,最终共获得1 122条大小在1 000-50 bp的带.经反向Northern杂交验证只有4条带特异的存在于两系中,分别命名为ogura-A205、ogura-A383、ogura-B307、ogura-B352.其中ogura-A205、ogura-A 383只在细胞质雄性不育系中表达,而ogura-B307、ogura-B352在保持系中呈现特异性表达,分析表明四个差异序列均为首次报道.其中ogura-A205、ogura-B307至今尚未发现与之相似的序列,有待于进一步研究;ogura-A383、ogura-352与报道的拟南芥、大白菜等的叶绿体基因的一些片段具较高相似性,推测ogura-A33、ogura-B352搅可能来源于花椰菜叶绿体基因组.以上结果为进一步阐明花椰菜细胞质雄性不育及育性保持的分子机制提供了新线索.     

不结球白菜新种质P70-203雄性不育细胞质类型的鉴定

本研究根据OguraCMS、PolimaCMS的不育性状相关的线粒体基因序列设计特异引物,对不结球白菜雄性不育系新种质P70-203及其保持系P60-27-1进行PCR分析.研究结果表明,Polima引物P3/P4,P5/P6在不育系与可育系中均无扩增条带;Ogura引物P1/P2在不育系中扩增出750 bp的特异片段,但可育系中无扩增条带.将扩增的特异条带回收并测序,将得到的测序结果在NCBI中进行Blastn同源性比较,结果与青花菜Ogura(登录号:EU604643)和萝卜Ogura(登录号:AB055438)细胞质雄性不育同源性均达到99%.从分子角度初步推测:该雄性不育系新种质P70-203具有Ogura细胞质.     

辣椒雄性不育系SDH4基因的表达特性分析

为了探究线粒体电子传递复合体Ⅱ的关键酶基因(SDH4)与辣椒细胞质雄性不育的关系,该试验通过GenBank报道的辣椒线粒体基因组序列,特异引物扩增SDH4基因,并通过分析SDH4基因的时空表达及转录本编辑位点,以期找到辣椒细胞质雄性不育系9704A和保持系9704B的差异。结果表明:(1)从辣椒细胞质雄性不育系9704A和保持系9704B中获得的目的基因编码区片段长度一致,全长均为378bp,编码125个氨基酸残基。(2)辣椒保持系不同组织中SDH4基因表达存在差异,种子中表达最高,茎中表达最低。(3)在不同材料花蕾发育的同一时期,SDH4基因表达也不一致,在花粉母细胞减数分裂时期,不育系SDH4基因表达量明显低于保持系;而在造孢细胞增殖期、小孢子单核期和小孢子成熟期的表达量均高于保持系。(4)不育材料中SDH4基因在29位点出现RNA编辑,导致氨基酸由丝氨酸变为亮氨酸,增强了蛋白结构的疏水性能。研究认为,辣椒细胞质雄性不育系9704A和保持系9704B中SDH4基因的表达差异可能引起植物的能量代谢供应出现异常,从而导致雄性不育的产生。     

三例小麦细胞质雄性不育系线粒体DNA的扩增片段长度多态性分析

细胞质雄性不育是小麦杂种优势利用的重要途径,为了鉴定3例小麦雄性不育系的细胞质类型,对其线粒体DNA(mtDNA)进行扩增片段长度多态性(Amplified fragment length polymorphism,AFLP)分析。文中利用差速离心法和不连续蔗糖密度梯度超速离心法提取纯化小麦线粒体。结果表明:通过该提取方法获得的mtDNA,其质量和纯度能够满足PCR反应和遗传学分析。在64对选扩引物中,筛选到了4对特异性引物,其中引物E1/M7在ms(Kots)-90-110不育系扩增出3条特异条带;引物E4/M2在ms(Ven)-90-110不育系扩增出2条特异条带;引物E7/M6在ms(S)-90-110不育系中扩增出2条特异条带;引物E6/M4在ms(Kots)-90-110不育系中扩增出2条特异条带。这些特异引物可以用来作为鉴定具有粘果山羊草Aegilops kotschyi、偏凸山羊草Ae.ventricosa、斯卑尔脱小麦Triticum spelta 3类不育细胞质型小麦雄性不育系的细胞质分子标记,为研究小麦细胞质雄性不育机理奠定了分子基础。     

甘蓝型油菜细胞质雄性不育系301A线粒体不育基因片段分析

提取细胞质雄性不育系301A、212A和'陕3A'及其共同保持系'中双2号'线粒体DNA,根据已报道的Polima油菜细胞质雄性不育相关基因orf224序列设计引物,对3种不同来源的线粒体DNA PCR产物进行分析.结果显示,这3种甘蓝型油菜细胞质雄性不育材料所获得片段序列完全一致,且与已报道的Polima油菜线粒体中细胞质雄性不育相关基因orf224序列完全相同.研究表明,不育材料301A从分子角度讲属于Polima系统,不育系301A、212A和'陕3A'线粒体中与细胞质雄性不育相关线粒体基因片段orf224具有高度同源性.     

紫稻(Oryza sativa L.)线粒体ATP合成酶atp6基因转录本RNA编辑

紫稻(Oryza sativa L.)细胞质雄性不育系紫稻A是本实验室构建的新型细胞质雄性不育系。本研究使用PCR、RT-PCR、DNA测序等技术,得到了紫稻细胞质雄性不育水稻不育系(樱香A)及其保持系(樱香B)线粒体atp6基因转录本cDNA序列。通过与基因组序列比对发现:樱香Aatp6cDNA序列中,没有发生RNA编辑;而樱香Batp6 cDNA序列中有16个编辑位点,在樱香B cDNA序列16个编辑位点位于15个密码子中,所编码的氨基酸均发生改变:在1003位点由C替换为T,导致原来编码谷氨酰胺密码子(CAA)成为终止密码子(TAA),保证atp6 mRNA编码一个正常的ATP6多肽;而由于没有发生RNA编辑,樱香A mRNA就不能翻译成正常的多肽。研究表明,RNA编辑在合成正常的ATP6多肽的过程中具有至关重要的作用,同时也说明RNA编辑可能与细胞质雄性不育相关。     

紫稻(Oryza sativa L.)线粒体ATP合成酶 atp6 基因转录本 RNA 编辑

紫稻（Oryza sativa L.）细胞质雄性不育系紫稻A是本实验室构建的新型细胞质雄性不育系。本研究使用PCR、RT-PCR、DNA测序等技术,得到了紫稻细胞质雄性不育水稻不育系（樱香A）及其保持系（樱香B）线粒体atp6基因转录本cDNA序列。通过与基因组序列比对发现：樱香Aatp6cDNA序列中,没有发生RNA编辑;而樱香Batp6 cDNA序列中有16个编辑位点,在樱香B cDNA序列16个编辑位点位于15个密码子中,所编码的氨基酸均发生改变：在1003位点由C替换为T,导致原来编码谷氨酰胺密码子（CAA）成为终止密码子（TAA）,保证atp6 mRNA编码一个正常的ATP6多肽;而由于没有发生RNA编辑,樱香A mRNA就不能翻译成正常的多肽。研究表明,RNA编辑在合成正常的ATP6多肽的过程中具有至关重要的作用,同时也说明RNA编辑可能与细胞质雄性不育相关。     

青花菜Ogu不育胞质分子鉴定和序列分析

雄性不育是农作物利用杂种优势、进行轮回选择和群体改良的重要手段,在农作物生产中具有巨大的利用价值。该研究为了鉴定青花菜细胞质雄性不育材料的不育胞质类型,以期今后为青花菜种质资源的收集、利用及分子标记辅助育种提供新的不育标记。根据Gen Bank中orf138基因保守序列设计特异引物,对20个青花菜种质资源基因组DNA进行PCR扩增。结果表明:特异引物P1/P2在12个青花菜雄性不育基因型中均扩增出392 bp的片段,在8个可育基因型中未扩增出条带,与田间育性鉴定结果相符。获得青花菜Ogu胞质雄性不育的特异基因orf138序列,Gen Bank中的登录号为HQ149728;用Blastn在Gen Bank中进行同源性比对分析,发现12个不育材料的特异片段与已报道的萝卜Ogu CMS所具有的Ogu orf138基因(Genbank登录号:Z18896.1)同源度高达100%。序列同源比对发现orf138基因存在变异位点。研究结果可为青花菜雄性不育细胞质的分子鉴定、进一步阐明胞质雄性不育败育机理,以及指导青花菜新型不育系的创建和杂种优势高效利用提供理论依据。     

细胞质雄性不育花椰菜保持系特异分子标记的鉴定及序列分析

以花椰菜细胞质雄性不育系NK-6和相应保持系NK-6B为材料进行RAPD分析,筛选了406条RAPD引物,共获得了2160条清晰可辨的条带,平均每个引物产生5-10条。其中引物S2121在两系的扩增中表现出多态性,在保持系中特异扩增出一条934bp的片段。克隆、测序,根据测序结果设计特异性引物,将RAPD标记转化成特异PCR标记,命名为S2121900。经Southern点杂交分析及对单株和多份候选材料的检测证实该标记为花椰菜保持系所特有,可用于候选保持系的早期筛查。序列分析表明该片段与油菜、拟南芥线粒体上的序列有较高相似性,因此推测该片段亦可能来源于线粒体基因组。本研究为从另一角度解释花椰菜细胞质雄性不育的分子机制提供了新线索。     

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.     

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     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

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.