鹿回头岸礁造礁石珊瑚物种多样性的研究

定量分析鹿回头岸礁造礁石珊瑚群落的种类组成,选择α－多样性和β－多样性的度量方法,分析了该群落造礁石珊瑚种、属和科的多样性及其与所处生境的关系。结果表明：鹿回头岸礁造礁石珊瑚群落的物种比较丰富,多样性和均匀度指数都较高,但在不同地段之间存在着明显的差异。水深中等的地段（２．４￣５．０ｍ）的多样性指数高于较浅（１．５￣２．０ｍ）和较深（５．５￣６．５ｍ）地段;潮间带与潮下带之间和礁平台与向海斜坡之间     

海南三亚鹿回头造礁石珊瑚生长变化与人类活动的影响

采用全球珊瑚礁监测网络(GCRMN)推荐的永久样方法首次在国内开展珊瑚礁生长的监测和研究。在海南三亚鹿回头岸礁区建立了10个珊瑚礁永久样方,分别于2003年12月、2004年4月、2004年9月和2005年4月开展了4次造礁石珊瑚生长的现场监测,并对周边人类活动进行了相关调查。研究发现,鹿回头东北部岸礁区4个样方的珊瑚覆盖率稳定增长,珊瑚生长良好,监测期间的珊瑚生长覆盖率平均为3.1%,珊瑚死亡覆盖率平均为1.3%;中部和南部岸礁区5个样方的珊瑚覆盖率明显下降,珊瑚出现衰退,衰退范围有明显扩大,珊瑚生长覆盖率平均为2.2%,珊瑚死亡覆盖率平均达到7.9%。珊瑚新个体的繁殖数量极少,平均新生珊瑚数量近1个/m2,新生珊瑚覆盖率对珊瑚生长覆盖率的贡献较低。人类活动对鹿回头岸礁区珊瑚生长的影响主要有两类:一是捕捞、炸鱼、船只抛锚、潜水等物理破坏;二是沿岸养殖场和旅游餐馆污水排放产生的水质污染,导致珊瑚生长机理的破坏。其中,水质污染是造成中部和南部岸礁区样方珊瑚死亡的主要原因,与沿岸养殖场和餐馆的分布、排污时间以及排污量有密切关系。     

海南岛周边海域造礁石珊瑚的群落结构及其分布

基于形态学分类鉴定,并辅以分子标记,我们于2014–2015年调查分析了海南岛文昌云龙湾、万宁大洲岛、儋州磷枪石岛、昌江沙鱼塘村、三亚鹿回头海域造礁石珊瑚的种类组成和分布。结果表明,海南造礁石珊瑚的分布较为广泛,共鉴定出10科17属55种,其中鹿角珊瑚科、滨珊瑚科和蜂巢珊瑚科为优势科。各海域造礁石珊瑚的群落结构不同:南部三亚鹿回头海域以分枝状鹿角珊瑚为主,东部文昌云龙湾和万宁大洲岛海域分别以叶片状和分枝状蔷薇珊瑚为主,而西部儋州磷枪石岛和昌江沙鱼塘村则分别以团块状滨珊瑚和蜂巢珊瑚为主。不同的地理环境使海南岛周边海域珊瑚礁群落呈现出不同的演替型,具有明显的地域性分布特点。5个不同海域造礁石珊瑚的覆盖率和多样性指数依次为:三亚鹿回头文昌云龙湾昌江沙鱼塘村万宁大洲岛儋州磷枪石岛,覆盖率和多样性指数具有明显的正相关性。与2005–2010年的调查结果相比,文昌云龙湾和万宁大洲岛保护区造礁石珊瑚的覆盖率和多样性指数有所上升,昌江沙鱼塘村和三亚鹿回头相对稳定,儋州磷枪石岛则下降比较明显。死亡率较高的是昌江沙鱼塘村邻近海域,且多为最近半年内死亡。人类活动(保护性或破坏性)极大地影响着造礁石珊瑚的多样性、覆盖率和死亡率。     

三亚珊瑚礁保护区珊瑚礁生态系统现状及其健康状况评价

为评估三亚珊瑚礁国家级自然保护区珊瑚礁生态系统的健康状况,本文选取东岛、鹿回头、大东海3个站位调查了珊瑚礁群落、珊瑚礁鱼类和大型底栖动物。通过对比分析历史资料、珊瑚礁现场生态调查与监测及组织专家评审,筛选出一、二级指标并设置权重,使用综合指数计算了三亚珊瑚礁保护区珊瑚礁生态系统健康指数。结果显示,三亚珊瑚礁保护区内共有造礁珊瑚10科21属37种,软珊瑚3种,造礁珊瑚覆盖率和软珊瑚覆盖率分别为14.31%和0.19%,其中鹿回头造礁珊瑚覆盖率最高,为21.58%。珊瑚礁鱼类共14科28属36种,其中,雀鲷科的种类数最多,为11种。鹿回头4 m断面珊瑚礁鱼类密度最大,为154尾/300 m~2。砗磲和龙虾极少发现,珊瑚天敌核果螺多见。东岛、鹿回头、大东海珊瑚礁生态系统健康状况均处于"一般"。本文所采用的方法是结合常规珊瑚礁监测可获得的指标进行评价,简便易操作,通过在三亚珊瑚礁保护区的实践,能够很好地反映珊瑚礁生态系统现状及其健康状况,科研和业务化监测部门均可应用。     

鹿回头库礁造礁石珊瑚物种多样性的研究

定量分析鹿回头岸礁造礁石珊瑚群落的种类组成,选择α－多样性和β－多样性的度量方法,分析了该群落造礁石珊瑚种、属和科的多样性及其与所处生境的关系。结果表明：鹿回头岸礁造礁石珊瑚群落的物种比较丰富,多样性和均匀度指数都较高,但在不同地段之间存在着明显的差异。水深中等的地段（２．４～５．０ｍ）的多样性指数高于较浅（１．５～２．０ｍ）和较深（５．５～６．５ｍ）地段;期间带与潮下带之间和礁平台与向海斜坡之间的两个过渡地带的生境条件复杂,物种多样性和种类分布的混杂程度都高于其他地段。     

广西涠洲岛造礁珊瑚种群结构的空间分布

对2007年和2008年调查的涠洲岛沿岸海域垂直海岸方向的6条主剖面上20条分断面的影像资料、样品鉴定等资料的分析,涠洲岛石珊瑚共出现10科22属46种,9个未定种;角蜂巢珊瑚属(Favites)、滨珊瑚属(Porites)、蔷薇珊瑚属(Montipora)为优势类群,其属级重要值百分比分别为25.78%、17.47%、15.11%;各主剖面珊瑚种群优势类群分布各有差异,以西南部的W2、东北部的W5的珊瑚属种为较多,均为8科13属,其石珊瑚属种分布均匀度略高;涠洲岛珊瑚分布自岸向海分为砂砾及珊瑚断枝带、石珊瑚稀疏带、石珊瑚繁盛带、柳珊瑚繁盛带4 个生物地貌带,石珊瑚分布较多的石珊瑚繁盛带主要分布于-1.39--5 m的水深范围内。石珊瑚形态组合以块状/亚块状与板块状为主要类型,覆盖程度以块状/亚块状占优。调查区受1998年的"厄尔尼诺现象"引起的全球性极高温事件和2008年1-2月的极低温气候事件及地域性不合理人类活动胁迫影响较大,枝状形态石珊瑚覆盖度、优势程度下降,已退出属种优势组合。     

西沙群岛海域造礁石珊瑚物种多样性与分布特点

2006年3-5月,采用国际通用的截线样带法对海南省西沙群岛主要珊瑚礁海域的18个岛礁造礁石珊瑚进行了实地调查,共记录13科45属188种,其中62个新记录种.整合文献资料,该海域共记录造礁石珊瑚13科50属204种,基本包括分布在我国(不含台湾省)的所有造礁石珊瑚科属和绝大多数种类.造礁石珊瑚以生长速度快的分枝状珊瑚为主.物种多样性最高的是华光礁海域、金银岛海域和永兴岛海域.聚类分析可以把18个调查岛礁分成3个类群:有人类居住的大型环礁群、独立岛礁群和无人居住的大型环礁群(华光礁).为了有效保护珍稀的造礁石珊瑚资源,按照其种类多样性和分布特点重点保护关键海域是十分必要的.     

基于RFLP技术的鹿角杯形珊瑚共附生固氮菌多样性分析

对三亚湾鹿回头与西沙石岛的常见鹿角杯形珊瑚(Pocillopora damicornis)的固氮酶nif H基因多样性进行了分析,并对其共附生固氮微生物多样性进行了比较。利用Taq I和HaeⅢ两种限制性内切酶分别对三亚湾珊瑚的粘液(SYN)、组织(SYZ)和西沙珊瑚组织(XSZ)的阳性克隆子进行聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析,得到了23,25和13个OTUs,文库的覆盖率分别为90.3%,87.5%和94.1%,多样性指数Shannon-Wiener指数(H)分别为2.28,3.02和2.08,Evenness指数(E)分别为0.5,0.65和0.56。研究结果表明:1)3个文库重要组成部分都是绿菌门(Chlorobia)和变形菌门(Proteobacteria)α-亚门、γ-亚门、δ-亚门细菌;2)3个文库绝大部分OTUs的最相似序列来自珊瑚礁、海绵、水体、沉积物等环境中的不可培养细菌,反映鹿角杯形珊瑚组织和粘液可能蕴含着丰富的尚未被培养的固氮菌资源;3)发现了两大重要的类群——分别与绿菌门和脱硫弧菌属(Desulfovibrio)细菌序列最相似的类群,它们通过为珊瑚共生体提供有机氮源参与到珊瑚白化的调节或恢复过程中,在珊瑚共生体营养物质的循环中充当重要角色;4)从多样性指数分析可以看出,SYZ的固氮微生物多样性高于SYN,SYZ的固氮微生物多样性高于XSZ,反映了鹿角杯形珊瑚生活的地理位置不同,固氮菌共附生的生态位不同(如珊瑚粘液、组织等不同部位),都将导致珊瑚共附生固氮菌多样性的差异。     

珊瑚礁区的生物多样性及其生态功能

珊瑚礁区生物多样性程度可以与陆地热带雨林相提并论,目前关于珊瑚礁物种多样性及其空间分布特征方面研究进展迅速,是生物多样性研究的重要基地。作为一种生态资源,珊瑚礁还具有重要的生态功能,近年来由于全球气候逐渐变暖、人类活动影响不断加剧,导致其生物多样性缩减、生态功能严重退化。珊瑚礁生态系统多样性、遗传多样性已成为珊瑚礁研究热点,珊瑚礁生态环境效应和保护管理方面的研究也越来越受到重视。我国珊瑚礁主要分布在广阔的南海海域和海南岛、台湾岛、香港和广东广西沿岸,礁区生物种类繁多,多样性程度较高,以往研究主要涉及地质、地貌、生物、环境等方面,现今和今后一段时间里迫切需要加强生物多样性和生态功能研究,以确保更有效地保护和管理珊瑚礁。     

南沙群岛珊瑚礁浮游动物多样性与群落结构

珊瑚礁是地球上已知的海洋生物多样性最高的生态系统,为了深入分析珊瑚礁的浮游动物多样性和群落结构,2004年5月5-15日在南沙群岛渚碧礁布设10个大面站(漏湖、礁坪各5个)和1个连续站(位于礁坪),使用网目孔径分别为169 μm和505 μm的两种浮游生物网进行垂直拖网采样.结果表明:共鉴定浮游动物种类96种和幼虫17个类群(或类型),其中桡足类最多,达65种,其次是幼虫;浮游动物数量丰富-根据169 μm网具样品的数据,平均丰度高达926.0±1,155.8 inds./m3,优势类群依次是桡足类、被囊类和幼虫,优势种为奥氏胸刺水蚤(Centropages orsinii)、珍妮纺锤水蚤(Acartia shuzheni)、长尾住囊虫(Oikopleura longicauda)、梭形住囊虫(O.fusifornis)和腹足类面盘幼虫(Gastropoda veliger);渚碧礁浮游动物空间分布差异相当显著,漏湖区形成与礁坪区不同的群落,前者种类多、丰度高、优势种突出、均匀度低,而后者则完全相反,浮游动物群落的空间变化是由珊瑚礁礁盘的空间异质性所造成.浮游动物昼夜变化明显,夜间出现的种数和平均丰度分别是日间的4.6和46.2倍.浮游动物群落以终生浮游生物的种类和数量占多数,它们来源于礁外海水,有的也属于礁栖类型.在珊瑚礁中,中小型浮游动物无论在种类还是丰度方面都占有非常重要的位置.     

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.