山羊KAP8.2基因的克隆表达及分析

目的：研究不同品种山羊和驯鹿高甘氨酸,酪氨酸（HGTKAP8）I型蛋白KAP8．2在核苷酸和氨基酸水平的差异,以及KAP8．2mRNA在内蒙古白绒山羊皮肤中的表达。方法：以阿尔巴斯白绒山羊KAP8．2设计特异引物,扩增马头山羊、吐根堡奶山羊、藏山羊和驯鹿KAP8．2基因的编码区,克隆测序并分析。体外制备地高辛标记的KAP8．2cRNA探针,通过原位杂交法在山羊皮肤组织切片上进行定位。结果：发现KAP8．2编码区在核苷酸和氨基酸水平的同源性较高,但也有差异,这可能是毛发性质不同的诸多原因之一。KAP8．2mRNA在成年10月份皮肤、胚胎125d皮肤初级和次级毛囊的皮质层均有强烈的表达。结论：KAP8．2是胚胎和成年山羊皮肤初级和次级毛囊的皮质层的组成成分,不同地区、不同品种山羊及驯鹿的KAP8．2在核苷酸和氨基酸水平同源性较高。     

阿尔巴斯白绒山羊KAP6家族cDNA的特征分析

在构建内蒙古阿尔巴斯白绒山羊次级毛囊兴盛期皮肤组织cDNA文库的基础上,随机挑取636个克隆从5’端开始测序,对序列进行特征分析。分析结果表明有41个ESTs与绵羊KAP6-1基因同源性大于95％,且期望值小于1e-10,进一步分析可被分为6个Qusters。从每个Cluster中挑取一个全长cDNA序列,其核苷酸序列和预测编码的蛋白质序列表明AY310753与绵羊KAP6-1最为相似、AY310750差别最大,AY310751和AY310752在编码区分别缺少36个的核苷酸或12个的氨基酸。     

绒山羊70d胚胎皮肤小分子RNA文库构建及miRNA鉴定

目的:miRNA是一类21~23个核苷酸的单链小分子RNA,最近发现miRNA对哺乳动物毛囊的发育和维持具有重要作用。为了研究miRNA在绒山羊次级毛囊发育中的作用,可以为人工调节绒毛生长和提高羊绒产量提供新的线索。方法:该文构建了绒山羊70 d胎儿胚胎体测部皮肤小RNA文库,库容量为2.5×107。随机挑选192个克隆提取质粒进行序列分析,序列经GenBank Blastn和mirBase搜索比对。结果:结果显示有32个序列和绒山羊及其它动物的miRNA高度同源,可以确定是山羊的miRNA。这些miRNA代表19个不同的miRNA序列,其中9个已注册,其余10个代表新的绒山羊miRNA。在克隆的miRNA中,miR-199a*和miR-424的拷贝数最高,分别达到6个和3个,表明它他们在绒山羊次级毛囊发育期间的皮肤中非常活跃,可能有重要的生物学功能。结论:从绒山羊70d胚胎皮肤中鉴定了19个miRNA,这些miRNA可能参与绒山羊次级毛囊发育的调控。     

山羊KRTAP26-1基因鉴定及其遗传特征研究

角蛋白关联蛋白(keratin-associated proteins,KAPs)是羊毛和羊绒的主要结构成分,决定了它们的理化性质。在人类、家犬、小鼠和大鼠中已描述了高硫蛋白KAP26-1的编码基因,但在山羊中该基因尚未被鉴定。本研究以人类KRTAP26-1基因编码区序列为模板,利用BLAST软件,在山羊基因组中发现了与人类KRTAP26-1基因具有高度同源性的序列并被假定为山羊的KRTAP26-1基因。PCR-SSCP分析发现,在5个山羊群体的605个个体中有4条不同的核苷酸变异序列(定义为A~D)。序列同源性和进化树研究结果表明,这4条序列与已鉴定的其它山羊KRTAPs基因序列有较低的同源性,但与人类、家犬、小鼠和大鼠的KR-TAP26-1基因序列具有最高的同源性。这说明发现的这4条序列是山羊KRTAP26-1基因的等位基因。4个等位基因的编码区内,共发现了6个SNPs位点,其中3个是非同义突变,造成了氨基酸序列的变化。4条多肽链含有36~38个磷酸化位点。5个山羊群体均处于中度多态,但是等位基因频率分布在不同群体间有差异。等位基因A、B和D在5个山羊群体中均出现,但C在中卫山羊中没有出现。结果表明,山羊KR-TAP26-1基因有较为丰富的核苷酸序列变异,这些变异可能与绒山羊的产绒性能有关。     

绵羊ILK基因的克隆及其在毛囊生长期的表达

整合素连接激酶(ILK)是一种支架蛋白,在毛囊发育过程中发挥重要作用。文章利用PCR技术,首次获得绵羊ILK基因的编码区全长序列,并进行了生物信息学分析;同时对该基因的组织表达谱及其在不同绵羊品种毛囊生长期皮肤组织中的表达变化进行了研究。结果表明,绵羊ILK基因ORF全长1 359 bp,编码452个氨基酸。ILK蛋白结构经预测含有3个锚定重复序列和1个激酶结构域,并存在多个磷酸化位点和蛋白激酶C的磷酸化位点。半定量RT-PCR结果显示该基因在绵羊心脏、肝脏、脾脏、肺脏、肾脏、骨骼肌、皮肤和小肠组织中均有表达,皮肤、脾脏和肝脏中表达量较高;实时荧光定量PCR结果表明在3~5月份(毛囊生长起始期),ILK基因在中国美利奴超细型和哈萨克羊皮肤组织中的表达水平较高并均呈逐月上升趋势;在6~10月份(毛囊生长期),中国美利奴超细型皮肤ILK基因表达水平高于同期的哈萨克羊。分析认为ILK可能在调控绵羊次级毛囊生长发育过程中起一定作用。     

人类新基因WDR70的克隆及初步研究

运用基于基因组数据库的特定基因同源新基因的克隆策略得到一个人类新基因WDR70 ,该基因编码一个包含 12个WD4 0结构域的蛋白。WDR70的cDNA序列长 2 2 6 6bp ,预测编码蛋白含 6 30个氨基酸 ,理论分子量为 70× 10 3 u ,染色体定位为 17p13.1。以小鼠胚胎为模型进行整体原位杂交 ,结果显示WDR70基因在 8.5d小鼠胚胎中没有表达 ,而在 9.5d和 10 .5d的小鼠胚胎的脑部有特异表达。由此推断该基因对胚胎期脑部的发育有重要的影响。     

与绵羊KAP6-1相似的6个绒山羊全长cDNA的克隆与序列分析

用SMART^TM技术构建了绒山羊体侧部皮肤组织的cDNA文库,随机挑选克隆提取质粒,用M13正向测序引物对插入片段进行测序,得到636个cDNA序列。与GenBank数据库比对,有41个序列与绵羊角蛋白关联蛋白(Keratin Associated Protein,KAP6-1)cDNA高度同源。41个序列可归为6个不同的cDNA,GenBank登陆号分别为AY310749、AY310750、AY310751、AY310752、AY310753和AY310754。与绵羊KAP6-1基因组基因比较,推测这6个序列为全长cDNA,分别为编码82、84、71、71、83和83个氮基酸的碱性蛋白质,甘氮酸和酪氮酸的含量大于60％,它们之间核苷酸序列的一致性大于55．4％,读码框氮基酸序列的一致性大于79．8％。与其他物种KAP6s比较,绒山羊的6个eDNA和绵羊的KAP6-1 cDNA的序列一致性最高,为81．9％～98．8％,不同物种KAP6-1之间氮基酸序列一致性大于50％。     

藏山羊GEM基因克隆及组织表达分析

本研究旨在克隆获得藏山羊GEM基因序列,预测其生物学功能,并阐明其组织表达特征。利用TA法克隆获得藏山羊GEM基因序列,并利用qPCR技术检测该基因在不同组织中的表达丰度。结果显示,藏山羊GEM基因序列1 096 bp,CDS区为936 bp,共编码311个氨基酸;GEM蛋白具有磷酸化位点和糖基化位点共33个,为不稳定碱性疏水蛋白质,主要在细胞核发挥生物学作用;藏山羊GEM基因的核苷酸序列和氨基酸序列均与反刍动物的序列具有很高的同源性;GEM基因在藏山羊肺组织中高表达(p0.01),其次高表达于脾组织(p0.01),均极显著高于其他组织。本研究为进一步了解藏山羊GEM基因功能提供基础数据。     

华山姜中钙调素基因的克隆及其RNA原位杂交

本文报道了华山姜中钙调素cDNA的核苷酸序列以及由此推导的氨基酸序列。并用原化杂交的方法检测其在花器官中的时间表达模式。用[^32P]d-CTP标记的小草蔻-Alpinia hainanensis AGAMOUS（AG）cDNA的MADS-domain作为探针筛选华山姜的cDNA文库．得到一个钙调素蛋白相关克隆．命名为AoCAM。华山姜钙调素AoCAM的cDNA全长518bp．有一个包含149个氨基酸的开放读码框．编码区起始于第54个核苷酸,终止于第501个核苷酸。AoCAM与拟南芥、小麦、大豆、矮牵牛、玉米的钙调素氨基酸序列比较同源性高达95％。RNA原位杂交表明钙凋素基因和花瓣、雄蕊、雌蕊细胞中大量表达。钙调素基因的表达强度随不同的发育阶段而变化：花发育早期在花的各器官中部表达强烈,以后逐渐减弱并向特定部位集中．如花粉囊、唇瓣、花柱和胚珠等分生能力较强的细胞中表达较强。     

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.     

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).     

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.