光棘球海胆(Mesocentrotus nudus)TGF-β基因克隆及其对海水酸化的响应

旨在明确光棘球海胆(Mesocentrotus nudus)转化生长因子-β(transforming growth factorβ,TGF-β)基因的序列及结构信息,探明该基因在海水酸化胁迫下的表达模式。利用同源克隆和cDNA末端快速扩增(RACE)技术首次获得光棘球海胆TGF-β基因(命名为MnTGF-β)的全长cDNA序列。结果显示:(1)光棘球海胆TGF-β基因的cDNA全长为2 299 bp,其中5'非编码区长度为745 bp,3'非编码区长度为261 bp;开放阅读框(ORF)长度为1 290 bp,编码430个氨基酸,相对分子量为48.31 kD,理论等电点为5.34。(2)同源性及系统进化分析显示,光棘球海胆MnTGF-β蛋白序列与紫球海胆(Strongylocentrotus purpuratus)SpTGF-β2蛋白序列高度保守(同源性97.69%)。(3)实时荧光定量PCR(qRT-PCR)检测发现,MnTGF-β基因在光棘球海胆性腺、体腔液、肠、围口膜、管足5种组织中均有表达,其相对表达量从高到低依次为:管足围口膜肠体腔液性腺。(4)与自然海水组(pH 8.06±0.01)相比,当海水△pH为-0.3时,随酸化时间延长,MnTGF-β基因在光棘球海胆性腺中的相对表达量呈先升高而后极显著降低(P0.01)再极显著升高(P0.01)趋势,在管足中的相对表达量呈现极显著上调趋势(P0.01),而在肠组织中的相对表达量则先极显著降低(P0.01)而后显著升高(P0.05);当海水△pH为-0.4和-0.5时,随酸化时间的延长,MnTGF-β基因在光棘球海胆性腺和管足中的相对表达量呈现先降低后升高的趋势,而在肠组织中的相对表达量则呈现极显著降低趋势(P0.01)。     

光棘球海胆seali基因克隆及表达特性分析

seali基因隶属于PIWI超家族, 其编码的RNA结合蛋白在生殖细胞发育过程中发挥重要作用。研究经同源比对从光棘球海胆(Mesocentrotus nudus)性腺转录组数据库中筛选得到seali基因片段, 随后通过cDNA末端快速扩增技术(Rapid amplification of cDNA ends, RACE), 获得其全长cDNA序列。光棘球海胆seali基因cDNA全长3462 bp, 其中3′UTR长度为416 bp, 5′UTR长度为180 bp, 其中3′UTR的加尾信号并非经典的AAUAAA或AUUAAA, 而是较少见的AAUACA。开放阅读框(Open Reading Frame, ORF)2862 bp, 编码954个氨基酸, 具有保守的PIWI和PAZ结构域, 多重序列比对和系统进化分析结果表明其属于Argonaute家族的PIWI亚家族成员。荧光定量PCR技术检测结果表明, Mnseali基因在光棘球海胆性腺、肠、管足和体腔细胞中均有表达, 在性腺中表达量最高。此外, Mnseali基因为母源因子, 在整个胚胎发育时期均有表达。在卵巢中, 随着卵母细胞的成熟, Mnseali的表达量逐渐升高, 而仅在成熟期的精巢中表达量显著上调。RNA原位杂交结果表明, Mnseali在光棘球海胆性腺的生殖细胞中特异表达, 是光棘球海胆生殖细胞标记基因。该研究为海胆生殖细胞发育相关的研究提供了支撑。     

流速对光棘球海胆行为和生长的影响

海胆在海藻床生态系统结构和功能调控中发挥重要作用。深入理解流速对海胆摄食和生长的影响具有重要的生态学研究价值。研究了长时间(49 d)不同流速(2 cm/s, 10 cm/s和20 cm/s)对光棘球海胆幼胆(Mesocentrotus nudus,壳径：约20 mm)摄食行为、摄食量和生长的影响，以评估不同流速下，海胆摄食行为和生长的差异。实验结果表明，流速对光棘球海胆的存活无显著影响，但显著影响其生长。2 cm/s下海胆的壳径和体重显著大于10和20 cm/s。在实验开始后的第2周和第3周，2 cm/s下海胆的体重和壳径已显著高于20 cm/s。流速显著影响光棘球海胆的摄食量(P<0.001)和觅食行为(20 cm/s,P=0.004),但口器咬合行为未受显著影响(P=0.113)。管足附着时间在流速为10 cm/s和20 cm/s下显著长于其在2 cm/s。同样的，相较于2 cm/s(P=0.02)和10 cm/s(P=0.03),20 cm/s的流速可显著削弱光棘球海胆的翻正行为。综上，高流速(20 cm/s)通过影响海胆管足活动削弱其觅食行为(而非摄食行为),进而降低其...     

中间球海胆、光棘球海胆及杂交F1代(中间球海胆♀×光棘球海胆♂)群体遗传多样性AFLP分析

应用AFLP技术对中间球海胆、光棘球海胆及杂交F1代(中间球海胆♀×光棘球海胆♂)群体的遗传多样性进行了分析。结果表明, 4对引物共扩增得到272个位点, 其中269个多态位点, 总的多态位点比例为98.89%。3个群体的香农多样性指数分别为: 0.2331 ± 0.1273、0.2005 ± 0.1385和0.2625 ± 0.1067。群体内遗传相似度分别为: 0.6876 ± 0.0523、0.6501 ± 0.0548和0.6552 ± 0.0553。分子方差分析(AMOVA)结果表明, 变异来源有25.39%来自群体间, 有74.61%来自群体内, 群体内的遗传多样性比较丰富。尽管杂交海胆在表型上可以明显分成两种类型, 但是通过AFLP统计的遗传距离进行的个体聚类却随机聚在一起, 不能分成两个群体。     

MYP基因在中间球海胆及杂交海胆生殖腺不同发育时期的转录表达差异

摘要: 应用实时荧光定量PCR技术对主要卵黄蛋白(Major yolk protein, MYP)基因在中间球海胆和杂交海胆(中间球海胆♀×光棘球海胆♂)的生殖腺不同发育时期的转录表达差异进行了分析。结果表明, MYP基因在海胆雌雄个体生殖腺中转录水平上的表达差异不明显; MYP基因在中间球海胆生殖腺发育的4个时期的表达呈快速下降的趋势, 而在杂交海胆呈缓慢下降的趋势。在分析的生殖腺4个发育期中, 中间球海胆雌雄个体 MYP 基因的表达量(以18S rRNA为参照)分别从44.55%和41.17%下降到9.59%和1.83%; 杂交海胆的雌雄个体分别从37.66%和36.66%下降到19.22%和12.55%。MYP基因的转录表达量差异与杂交后生殖腺产生的变异密切相关。     

中间球海胆、光棘球海胆及杂交F1代（中间球海胆♀×光棘球海胆♂）群体遗传多样性AFLP分析

应用AFLP技术对中间球海胆、光棘球海胆及杂交F1代（中间球海胆♀×光棘球海胆♂）群体的遗传多样性进行了分析。结果表明,4对引物共扩增得到272个位点,其中269个多态位点,总的多态位点比例为98.89%。3个群体的香农多样性指数分别为：0.2331±0.1273、0.2005±0.1385和0.2625±0.1067。群体内遗传相似度分别为：0.6876±0.0523、0.6501±0.0548和0.6552±0.0553。分子方差分析（AMOVA）结果表明,变异来源有25.39%来自群体间,有74.61%来自群体内,群体内的遗传多样性比较丰富。尽管杂交海胆在表型上可以明显分成两种类型,但是通过AFLP统计的遗传距离进行的个体聚类却随机聚在一起,不能分成两个群体。     

基于5.8SrDNA/ITS序列的内蒙古棘豆属植物分子系统学分析

对12种34个地理种群的内蒙古棘豆属植物核糖体ITS区段和5.8S基因序列进行比较分析,并采用Maximum Likelihood法构建系统发育树.结果表明:支持棘豆属植物为单系起源,支持《内蒙古植物志》将黄毛棘豆(Oxytropis ochrantha)、多叶棘豆(O.verticillaris)、二色棘豆(O.bicolor)和砂珍棘豆(O.racemosa)归入真棘豆亚属(Subgen.Euoxytropis)轮叶棘豆组(Sect.Baicalia Stell.ex Bunge)的观点.推测多叶棘豆和砂珍棘豆ITS2区段出现的C/T转换可能是其部分种群混杂在其他物种中的主要原因,但基因转换对于系统发育的影响仍尚未可知.研究不支持传统分类学上对鳞萼棘豆(O.squammulosa)与刺叶柄棘豆(O.aci ph ylla)的划分,系统发育树显示二者聚为一支,而非与传统分类学上界定的同组或同亚属植物形成一支;结合植物地理学研究结果,认为刺叶柄棘豆与鳞萼棘豆为地理替代种.推测刺叶柄棘豆可能为多系起源物种.线叶棘豆(O.fili formis)和东北棘豆(O.coerulea与真棘豆亚属物种构成姐妹群,而非单室棘豆亚属植物.研究认为在物种界定过程中,只将少数几个形态学特征作为主要分类依据欠妥.     

中国带鱼科鱼类一新纪录--棘背带鱼

棘背带鱼(新称)Assurger anzac (Alexander, 1916)(图1)隶属带鱼科Trichiuridae,棘背带鱼属(新称)Assurger Whitley,1933.标本1尾,全长2 172 mm,体长2 115 mm,于1996年10月采自舟山群岛海域.棘背带鱼属和棘背带鱼在我国均为新纪录.     

中国棘蚁蛉族分类研究(脉翅目,蚁蛉科)

对中国棘蚁蛉族Acanthaclisini进行了分类研究和修订,共记述中国棘蚁蛉族4属5种(包括2新纪录属、2新纪录种):尾棘蚁蛉Acanthaclisis pallida Mclachlan,单中大蚁蛉Centroclisis negligens(Navás),南击大蚁蛉Heoclisis kawaii(Nakahara),追击大蚁蛉Heoclisis japonica(Maclachlan)和黎母硕蚁蛉Stiphroneura inclusa(Walker).其中棘蚁蛉属Acanthaclisis和硕蚁蛉属Stiphroneura为中国新纪录属,尾棘蚁蛉A.pallida Mclachlan和黎母硕蚁蛉S.inclusa(Walker)为中国新纪录种.确定了Alloclisis hainanica Yang为Centro-clisis negligens(Navás)的新异名,Neriga limoiana Yang为Stiphroneura inclusa(Walker)的新异名.编写了中国棘蚁蛉族分种检索表.标本保存在中国农业大学昆虫系标本馆和中国科学院动物所.     

海胆胚胎染色体标本制作方法

在19世纪末和20世纪初,许多研究者研究海胆的染色体(Makino 1950),用切片法从受精卵制作染色体标本。然而为了统计染色体数目,这种方法不是很适用的,因为海胆具有很多小型的染色体。Pinney(1911)观察到,在Hipponoe esculenta的切片中有30、32或33个染色体。Tennent(1912)报告毒棘海胆(Ta-xopneustes variegatus)的染色体数目为36、37或38;H.esculenta的为33或34,都没有确定的论述。最近用胚胎的整体染色装片(Makino和Alfert,1954)或用盖玻片轻压胚胎法(Agrell,1957),然而由于染色体没有充分散开,准确地观察染色体仍没有适当的方法。     

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.