进展中的纤毛虫学研究:新格局、新窗口与新拓展

本文综述了作者及所在团队近30年来在海洋纤毛虫领域所取得的系列创新型研究成果。主要概括如下:(1)开拓了中国沿海自由生活类群的区系分类、生态学以及养殖动物病原学等研究,覆盖了温带、热带海区各生境中纤毛门内40余目级阶元,构建了我国长期缺失的海洋类群的物种与基因多样性资料,阐述了特定时空格局下的区系构成与群落演替规律以及主要海水养殖动物的危害性病原等,建立了包括新纲、新目、新科、新属和新种等在内的大量新阶元,系统地描述了近千种的形态分类学信息;(2)完成了1 700余种/种群DNA库、1 400余条标记基因库等纤毛虫遗传资料库的构建;在标记基因序列分析基础上,对纤毛门13个纲、55个目级阶元的系统发育进行了深层次的梳理和探讨,解答了纤毛虫系统演化、阶元定位等方面的诸多科学问题;(3)在细胞发生学研究方面,以腹毛类纤毛虫为材料,围绕无性生殖期间的个体发育,研究刻画了100余种-属的细胞分化与模式构建过程,揭示了大量发生学新现象并形成了领域内首部全视角专著《腹毛类纤毛虫的细胞发生模式》;(4)在基因组学与基因进化研究方面,针对进化地位特殊、环境依赖以及类群代表性种类,阶段性地完成了近百种单细胞基因组的常规测序和6个种的深度分析,研究揭示了钩刺斜管虫大小核基因重组模式等进化生物学新现象;(5)在基因条形码研究方面,以重要模式生物游仆虫属、草履虫属等类群为材料,开展了DNA条形码的筛选和技术优化探索,提出了COI基因和28S rRNA基因D1～D2区可有效刻画近缘种或隐存种这一新观点;(6)在表观遗传学研究方面,探讨了四膜虫组蛋白单甲基化酶TXR1对复制延伸的影响、N6-腺嘌呤甲基化的全基因组分布模式及决定因素、反式和顺式作用元件对核小体分布的协同作用以及RNAi和Polycomb通路关键蛋白对转座子沉默与激活的调控作用与机制。上述研究成果历史性地改变了纤毛虫学研究格局,极大地提升了我国原生动物学研究的国际地位。     

海水养殖水体中危害性纤毛虫原生动物研究Ⅰ.盾纤目习见类群的口器结构及鉴别特征

对发现自我国北方海区养殖环境中危害性盾纤目纤毛虫的常见类群 (16属 )之口器结构、一般形态学与鉴别特征以及属种模式做了概要性介绍。同时涉及了生活类型、已知种的分布范围、纤毛图式水平的示差鉴别及属级定义并借助模式图例为该类广泛分布而又不易识别的病害纤毛虫类群提供了一份简明的病原鉴定资料     

氨银法的新改良——一种应用于海洋纤毛虫永久制片的新方法

纤毛虫原生动物的大多数分类性状在活体观察或非染色状态下是不可见的,因而需借助各种染色技术加以显示。目前在纤毛虫的细胞学,遗传学,分类及形态学研究中应用的主要是一些特殊的银染法,蛋白银染色法,以显示其银线系统,纤毛下器,核器,皮膜结构及其它胞器。干银法和湿银法仅用来显示银线系及表层的纤毛图式。应用最广也最重要的是蛋白银染色法,可惜后者存在着耗时多、过程复杂、掌握困难,对许多类群不适用的缺点。由于制片方法上的限制,使许多有关的工作难以进行。     

侧毛虫科系统关系的探讨与属级定义的重厘订(纤毛门,腹毛目)

根据纤毛图式及细胞发生学特征 ,重新界定了腹毛目侧毛虫科纤毛虫 :侧毛虫、异毛虫、锥口虫、海尾柱虫、拟片尾虫以及拟翁口虫 6个相近属的定义。同时利用近祖 -衍化分析 ,探讨了其系统关系。     

黄渤海底栖纤毛虫分子多样性和生物地理学研究

对中国渤海、北黄海和南黄海三个海域底栖纤毛虫的分子多样性与生物地理学进行了研究。从底栖真核微生物18S rDNA的焦磷酸测序数据中提取出隶属于纤毛门的序列,并在此基础上分析了纤毛虫群落的阿尔法多样性和贝塔多样性。结果表明,纤毛虫操作分类单元的丰富度在渤海比北黄海和南黄海都高,但夏冬两季无显著差异。在所有检测的环境因子中,水体深度与阿尔法多样性的相关性最强。就纤毛虫群落组成上看,总体上旋唇纲的序列及操作分类单元丰富度均占优势地位（占比分别为77.0%和66.5%）;旋唇纲主要由环毛亚纲以及未能进一步分类的类群组成。底栖纤毛虫群落结构在三个海域之间显著不同,但夏冬两季无显著差异。从各主要类群的相对比例来看,唯有侧口纲的序列比例在三个区域间呈现显著的不同。偏门特尔分析表明,相对于地理距离和环境因子而言,水体深度在调控底栖纤毛虫群落结构中扮演者更为重要的角色。本研究同时也发现,超过60%的操作分类单元未能被进一步分类到纲或目级水平,约45%的操作分类单元与GenBank数据库中已描述种类的序列相似度低于或等于97%,表明在近海沉积物中可能存在大量待发现的纤毛虫类群或物种。本研究发现底栖纤毛虫阿尔法多样性从北黄海到南黄海降低的趋势,这一点与之前基于形态学方法的调查结果相似。然而,测序数据显示旋唇纲是最主要类群,而形态学调查表明前口纲和核残迹纲是主要类群。本文也探讨了可能造成分子与形态学研究结果差异的一些潜在原因。     

鲍人工养成阶段养殖环境中的周丛纤毛虫

应用定性和定量方法,研究了人工养成阶段杂色鲍Haliotis diversicolor外壳的周丛纤毛虫的种类组成和优势类群演变。共观察到3纲9目35属58种纤毛虫,缘毛类Peritrichida的种类最多,有23种。在养成阶段的早期,周丛纤毛虫的优势类群为钟虫类;在养成阶段的中、后期,周丛纤毛虫的优势类群演变为聚缩虫类,其中交替聚缩虫Zoothamnium alternans占绝对优势;文中还对各种环境因子对养殖环境中的周丛纤毛虫的影响进行了分析。     

五种管口类纤毛虫的形态学研究

管口目纤毛虫由于个体微小且大部分种类缺乏现代分类学的研究,是纤毛门中较混乱的类群之一。为进一步了解其形态性状的种群间差异,借助显微活体观察及蛋白银染色法对采自青岛、湛江和香港近岸的斯雷腹沟虫(Coeloperix sleighi)、尖绒毛虫(Microxysma acutum)、乙状轮毛虫(Trochilia sigmoides)、阿氏直毛虫(Orthotrochilia agamalievi)和近岸类偏体虫(Agnathodysteria littoralis)5种管口类纤毛虫进行了形态学再研究,依据新采集种群,对其活体形态和纤毛图式特征进行补足性描述。结果发现,斯雷腹沟虫、乙状轮毛虫和阿氏直毛虫的形态性状极为稳定,而新采集的尖绒毛虫和近岸类偏体虫种群在伸缩泡数目上同前人描述略有差异。     

喙突斜叶虫的形态学及分类地位的探讨

在对养殖水体病害纤毛虫调查中观察到一侧口目纤毛虫,经鉴定为喙突斜叶虫。借助蛋白银技术对其纤毛图式作了首次揭示,确定了其独立地位,同时还对其生境特征及与相近种的关系做了综合描述和探讨。研究中还进行了杀灭试验。     

鬃异源棘尾虫的形态学及细胞发生学研究

利用活体观察和蛋白银染色技术对鬃异源棘尾虫(Tetmemena pustulata(Müller,1786)Eigner,1999)漠河种群的形态学及细胞发生学进行了详尽的研究。研究表明:本种群与其他种群在活体形态和纤毛图式特征方面十分吻合。无性生殖期间细胞发生学表现出的主要特征如下:1)老口围带为前仔虫所继承,老波动膜仅在前部发生更新;2)后仔虫口原基为表层独立发生;3)老棘毛II/2、III/2与IV/3、IV/2、V/4分别参与前、后仔虫额-腹-横棘毛原基的构建;4)前、后仔虫额-腹-横棘毛原基I-VI以“1∶3∶3∶3∶4∶4”的方式分化形成棘毛;5)前、后仔虫的缘棘毛原基分别由老结构反分化形成;6)背触毛发生为尖毛虫模式,但2列背缘触毛原基源于右缘棘毛原基前端断裂。本研究为该种背缘触毛原基起源的首次揭示。     

鲍鱼幼苗培养池附板上的危害性纤毛虫及其优势类群研究

应用纤毛虫的定性和定量方法,研究了人工养殖幼鲍培养池中危害性纤毛虫的种类组成和数量变化过程及优势类群的种群动力学变化。共观察到16目、46属、68种纤毛虫,锐利Shun纤虫Aspidisca lynicaster、钟虫Vorticella sp.和双眉虫Diophrys histrix是优势种。还对幼鲍培养过程中危害性纤毛虫的密度、种类与幼苗附板上藻类密度、鲍苗密度等关系进行了分析。     

分子标记在纤毛虫原生动物系统学研究中的应用

综述同工酶、RFL P、RAPD、SAP、AFL P及序列测定技术在纤毛虫原生动物系统分类学研究中的应用。相较传统的形态分类学 ,分子标记可以从基因和分子水平上提供可靠而丰富的依据。作者就分子标记在该类动物系统分类学研究中的意义及现状作了回顾 ,并就其应用前景进行了探讨。     

Spatial information for coastal zone management: the example of the Banten Bay seagrass ecosystem,Indonesia

Geo-information technology can be useful in Integrated Coastal Zone Management (ICZM). The benefits lie in the fact that geo-information technology can process large amounts of spatial data and can integrate different types and sources of data. The general aim of this paper is to demonstrate these benefits. First, we argue that spatial databases and GIS can be used and are present in most of the policy analysis phases of ICZM. Then, we illustrate this with a case study about seagrass beds in Banten Bay, Indonesia. The development of a spatial database, including seagrass maps is described. An overlay analysis shows that the largest and most dense fields of seagrass, which are also the most important as habitat for commercial fish species, are located near past and planned shoreline developments. This and similar type of spatial analyses are very important to support ICZM decision-making at the district level. A good spatial information infrastructure to collect data and make this data accessible is a pre-requisite.     

A perspective on the Census of marine life. The role of natural history institutions for this programme

The Census of marine life programme (CoML) is expected to generate a large amount of information on the diversity, distribution, and abundance of marine communities, many of them new or poorly known. Institutions such as natural history museums can play a crucial role in providing the necessary tools to allow the CoML to advance knowledge in the fields of marine systematics and biogeography. These institutions can contribute taxonomic expertise to provide quality-controlled identifications of species; specimen collections to allow for cross-checking of occurrences and a historical context for new data; information, both paper and electronic, on taxonomy, ecology and other topics to enable researchers to review past work; education opportunities to inform the public about the results of current and past research on the marine world. Challenges for these institutions in the future include the recruitment, training, and retention of taxonomic experts, development of advanced molecular techniques for more reliable and faster species identification in certain groups, and integration of expertise and other taxonomic resources into research on scientific processes from start to finish.     

Are critically endangered fish back on the menu? Analysis of U.K. fisheries data suggest post-ban landings of prohibited skates in European waters

Skates (Rajidae) have been commercially exploited in Europe for hundreds of years with some species’ abundances declining dramatically during the twentieth century. In 2009 it became “prohibited for EU vessels to target, retain, tranship or land” certain species in some ICES areas, including the critically endangered common skate and the endangered white skate. To examine compliance with skate bans the official UK landings data for 2011–2014 were analysed. Surprisingly, it was found that after the ban prohibited species were still reported landed in UK ports, including 9.6 t of common skate during 2011–2014. The majority of reported landings of common and white skate were from northern UK waters and landed into northern UK ports. Although past landings could not be validated as being actual prohibited species, the landings’ patterns found reflect known abundance distributions that suggest actual landings were made, rather than sporadic occurrence across ports that would be evident if landings were solely due to systematic misidentification or data entry errors. Nevertheless, misreporting and data entry errors could not be discounted as factors contributing to the recorded landings of prohibited species. These findings raise questions about the efficacy of current systems to police skate landings to ensure prohibited species remain protected. By identifying UK ports with the highest apparent landings of prohibited species and those still landing species grouped as'skates and rays’, these results may aid authorities in allocating limited resources more effectively to reduce landings, misreporting and data errors of prohibited species, and increase species-specific landing compliance.     

虾夷扇贝Smad基因家族的鉴定及表达分析

Smad基因介导的细胞信号在调节动物发育和细胞干性方面起着至关重要的作用。由于其功能的多样性和重要性,Smad基因家族一直受到广泛的研究。然而,双壳贝类Smad基因家族缺乏系统的鉴定和分析。为了理解双壳贝类Smad基因家族的进化和生物学功能,本文在虾夷扇贝基因组鉴定出4个Smad基因,并对其遗传和表达特征进行了分析。时空表达谱显示,Smad3基因在虾夷扇贝受精卵和2~8细胞时期有较高的表达量,而在胚胎及幼虫阶段该基因表达量迅速降低,推测其在胚胎早期细胞分裂和分化过程中发挥重要作用。Smad6在胚胎发育早期表达量较低,在囊胚期及原肠胚时期表达量显著升高,可能与母源调控向合子型调控过渡的“中期囊胚转换”有关。Smads基因在各组织中也呈现了独特的表达模式,其中Smad3、Smad5和Smad6分别在肌肉、血细胞和鳃中表达量最高。而Smad4在各个组织内均有表达且表达量相似。实验结果暗示了Smad基因在虾夷扇贝中不仅参与协调了早期胚胎的发育,也与组织器官的形成和稳态有关。本研究有助于理解贝类Smad基因的进化及功能,为深入研究该基因家族在贝类中的生物学功能和调控机制奠定基础。     

翡翠贻贝鳃的组织形态学和超微结构观察

应用光镜和透射电镜观察翡翠贻贝鳃的组织形态学和超微结构．翡翠贻贝身体两侧各有一对鳃瓣,覆盖在内脏团之上,鳃瓣由众多鳃丝组成．与其它种类贻贝相似,翡翠贻贝鳃丝上皮可区分为前微绒毛柱状细胞、前侧纤毛柱状细胞、立方或扁平细胞和后微绒毛柱状细胞等4个不同区带．电镜水平下可观察到鳃丝上具微绒毛柱状细胞、具纤毛柱状细胞、立方或扁平细胞、间质细胞和粘液细胞等5种细胞类型．本文对鳃丝的组织形态学及各类细胞的超微结构与功能作了描述及讨论．     

满月蛤目(双壳纲:异齿亚纲)软体动物分类与系统演化研究进展

满月蛤目物种是海洋常见的双壳类软体动物,通常生活在有机质含量较高或化能生态系统中,是这两类生态环境中的主要类群。本文回顾了满月蛤目分类与系统演化的研究历史。随着受关注程度的增加以及技术手段的发展,世界范围内出现大量的分类和系统演化研究,但由于物种繁多、样品获取困难、贝壳形态多变,该类群的分类系统仍存在大量尚未解决的问题,且其物种多样性被严重低估。我国对该类群系统性的研究尚未开展。未来需加强标本采集,结合新技术进行整合分类学研究以摸清我国满月蛤目物种组成和区系特点,完善分类系统,进而对其起源演化、扩布路径等问题进行探究。     

Phytoplankton community dynamics assessed by ships-of-opportunity sampling in the northern Baltic Sea: A comparison of HPLC pigment analysis and cell counts

The dynamics of phytoplankton diversity constitute crucial data in environmental monitoring, food-web studies and ecosystem modeling. Proper assessment of phytoplankton community composition requires large investments in offshore sampling and taxonomic competence because these communities can change fundamentally on a weekly scale. Cheap and high-frequent offshore phytoplankton sampling can be achieved by using ships-of-opportunity, and in the present study we used the Alg@line facilities onboard a passenger ferry during its regular route between Finland and Sweden in the northern Baltic Sea. The first aim was to test if pigment analysis, as a cheaper alternative to cell counts, can be used to detect environment-correlated variation in phytoplankton communities. It has been shown that spatial variation (salinity differences) and variation throughout one annual cycle (changes in temperature and nutrients) were strongly reflected by pigment composition. The second aim was to test if pigment analyses and cell counts detect environment-correlated variation in phytoplankton communities equally well. It has been shown that spatial and seasonal variations were reflected by pigment composition while cell counts reflected seasonal variation only. This suggests that the pigment analyses detected aspects of the phytoplankton that were neglected or misinterpreted by cell counts. It is advocated that available resources of long-term studies, such as environmental monitoring, can be used more efficiently by utilizing the high ecological resolution of pigment composition in combination with high-frequent ships-of-opportunity sampling. To assess heterotrophic and/or toxic species, such programs could also include sampling for cell counts in a complementary manner, with actually performing counts only for crucial samples (e.g. between large community changes) as indicated by multivariate statistical analysis of pigment composition. Some aspects of analyzing phytoplankton data with multivariate statistics are also discussed.     

The contribution of rare species to coastal phytoplankton assemblages

Analysis of quantitative and qualitative composition of rare phytoplankton species was performed using a data set collected over a large geographic area (four eutrophic gulfs of the Aegean Sea, E. Mediterranean Sea) during 2002–2003. We examined the effects of excluding rare species on comparisons of species richness, diversity, similarity and niche breadth as well as the regional and seasonal contribution of rare species to cell abundance and carbon biomass. Overall, the total of 401 species included 182 rare species contributing 45.1% of the total species number. However, there was a considerable variation in this relationship among the other parameters, as rare species contributed only 6.4% of total cell abundance, 13.1% of total species diversity, 21.2% of total cell biovolume and 16.6% of total carbon biomass. The results showed that rarity may be a significant issue in studies detecting and quantifying phytoplankton community structure.     

Data rescue and re-use: Recycling old information to address new policy concerns

Information on past trends is essential to inform future predictions and underpin attribution needed to drive policy responses. It has long been recognised that sustained observations are essential for disentangling climate-driven change from other regional and local-scale anthropogenic impacts and environmental fluctuations or cycles in natural systems. This paper highlights how data rescue and re-use have contributed to the debate on climate change responses of marine biodiversity and ecosystems. It also illustrates via two case studies the re-use of old data to address new policy concerns. The case studies focus on (1) plankton, fish and benthos from the Western English Channel and (2) broad-scale and long-term studies of intertidal species around the British Isles. Case study 1 using the Marine Biological Association of the UK's English Channel data has shown the influence of climatic fluctuations on phenology (migration and breeding patterns) and has also helped to disentangle responses to fishing pressure from those driven by climate, and provided insights into ecosystem-level change in the English Channel. Case study 2 has shown recent range extensions, increases of abundance and changes in phenology (breeding patterns) of southern, warm-water intertidal species in relation to recent rapid climate change and fluctuations in northern and southern barnacle species, enabling modelling and prediction of future states. The case is made for continuing targeted sustained observations and their importance for marine management and policy development.