川北广元宣河兰多维列世宁强组的海绵和托盘类*

本文描述的化石材料是笔者于1987年在四川广元宣河宁强组内采得。经笔者鉴定和描述的计有海绵类Calycocoelia profunda sichuanensis subsp. nov.和托盘类Calathium sp.。Receptaculitids是表示以Receptaculites属为代表的一类海生生物的名字。Receptaculires是Deshayes(1828)从法文的属名Receptaculite(Defrance, 1827)改拼而成的。尼捷茨基(Nitecki)在1967年和1972年的文章已详细论及这个属名的沿革。1932年Waterlot描述比利时中泥盆统Receptaculites neptuni Defrance(它是Receptaculites的模式种)的标本时,从他提供的插图中,表明这种生物的个体呈杯状、瓶状和瓮状,其腔口是向上的。1962年科学出版社出版的《英汉动物学词汇》(第375页)把Receptaculites翻译为“     

西沙群岛永兴岛类符属一新种(弹尾目:等节科)

类符(虫兆)属Folsomina是由Denis(1931)建立的,至今只报道过一种,Folsominaonychiurina Denis,1931,为世界广布种。类符(虫兆)属由于触角第Ⅳ节上特殊的感觉器,缺角后器和眼,腹部第Ⅳ—Ⅵ节愈合等特征,很容易与等节(虫兆)科的其他属相区别。Gisin(1960)和Christiansen ＆ Bellinger(1980)将其归入符(虫兆)属Folsomia,但绝大多     

植物中的小类泛素修饰因子(SUMO)修饰系统

小类泛素修饰因子(SUMO)是一种可以通过异肽键修饰其他蛋白质的小分子多肽,是在动物中发现的类似于泛素的蛋白质修饰方式。它参与调节了植物对逆境反应、病源防御、脱落酸信号传递以及成花诱导等许多过程,是植物正常生长发育中必不可少的蛋白质修饰方式。文章就其研究进展作一简要介绍。     

白(既鱼)豚MHC基因类DQB1座位第二外元的序列变异分析

测定了45个克隆的白(既鱼)豚(Lipotes vexillifer)MHC Ⅱ类基因DQB座位第二外元172 bp的核苷酸序列,共获得15种序列,发现了22个变异位点.核苷酸的非同义替换明显多于同义替换,并造成了15个氨基酸的改变.氨基酸的替换趋于集中在假定的与抗原的选择性识别相关的位点附近.白(既鱼)豚DQB基因的核苷酸和氨基酸序列与文献报道的白鲸(Delphinapterus leucas)和一角鲸(Monodon monoceros)DQB1序列具有较高的同源性.氨基酸序列不具备人及其它一些灵长类动物DQB2基因所共有的基序(Motif),而与牛DQB1基因的基序相近,说明本研究得到的白(既鱼)豚MHC序列应属于类DQB1基因.同一个体出现了多种序列的情况,提示白(既鱼)豚的DQB基因可能存在着座位重复.白(既鱼)豚的类DQB1座位的序列中存在多种基序的不同组合,推测是由于基因转换造成的[动物学报 49(4):501～507,2003].     

北京鸭血清HDL主要载脂蛋白的高效液相层析分离及其理化性质

用高效液相层析(HPLC)对北京鸭血清高密度脂蛋白(HDL)的所有载脂蛋白(apo)分离纯化,得五个主要apo峰,经SDS-PAGE鉴定,均为单一带;并做了IEF、糖基含量分析;对其中含量高的四个apo峰样进行了氨基酸组成测定和N-端部分氨基酸序列分析;从所做理化性质的研究,发现北京鸭血清HDL中的主要apo为:A-Ⅰ、C-Ⅲ_o、apoC-Ⅲ_s(s=1,2)、apoC's及可能的A-Ⅲ,几乎不含E和A-Ⅱ_o北京鸭HDL中apo的上述组成特点明显不同于易患动脉粥样硬化(As)的人及兔等动物,在一定程度上决定了北京鸭HDL的形成与代谢具有其特点,该特点与北京鸭不易形成As密切相关。     

桂林岩溶石山青冈群落数量分类与排序

植物群落的数量分类和排序可以客观地揭示植物群落与环境之间的关系,从而能为植被恢复与重建、森林经营与管理和生物多样性保护等提供理论依据。基于群落学调查和环境因子测定数据,采用Ward聚类、双向指示种分析(TWINSPAN)和多元回归树(MRT)对桂林岩溶石山青冈群落进行数量分类,选用冗余分析(RDA)进行排序,分析其与环境因子之间的关系。结果表明:(1)3种分类方法所得结果基本一致,可将桂林岩溶石山青冈群落划分为3个群丛类型,分别为青冈-粗糠柴+龙须藤+红背山麻杆-三穗薹草群丛(Ass.Cyclobalanopsis glauca-Mallotus philippensis+Bauhinia championi+Alchornea trewioides-Carex tristachya)、青冈-龙须藤+红背山麻杆+干花豆-宽叶沿阶草+三穗薹草群丛(Ass.Cyclobalanopsis glauca-Bauhinia championi+Alchornea trewioides+Fordia cauliflora-Ophiopogon platyphyllus+Carex tristachya)、青冈-粗糠柴+干花豆-三穗薹草群丛(Ass.Cyclobalanopsis glauca-Mallotus philippensis+Fordia cauliflora-Carex tristachya);(2)冗余分析结果较好地反映出各群丛类型的分布格局及其与环境梯度的相互关系,在10个环境因子中,岩石裸露率、土壤含水量、pH值、全氮、全磷、全钾、速效钾这7个环境因子对群落的分布影响显著。土壤含水量和全钾含量可能是影响该植物群落物种组成与分布的重要生态因子。     

眼齿鸟再分析显示其蜥蜴属性（英文）

最近在白垩纪晚期缅甸琥珀中报道了一件小型头骨化石,原论文作者将其鉴定为一蜂鸟大小的鸟翼类(Avialae)恐龙,并命名为宽娅眼齿鸟(Oculudentavis khaungraae)。基于这件标本,原论文提出了中生代恐龙(包括鸟翼类)体型演化和生态类型的种种假设。但原论文的插图和描述均显示这件头骨呈现出多个鳞龙类的典型形态学特征,这些特征很少在主龙类中出现。原论文先验地将标本鉴定为鸟翼类,继而进行仅包括鸟翼类作为内类群的系统发育分析。该分析的取样过于局限,不能对其系统位置归属提供有价值的参考。本文对宽娅眼齿鸟正型标本的计算机断层扫描原始数据重新进行了重建、渲染和分析,结果揭示了多个新的头骨形态学特征,包括侧生齿、开放的下颞孔以及头骨腭面着生有腭齿等,这些均为典型的鳞龙类/有鳞类特征,不支持其主龙类,遑论鸟翼类的系统位置归属。基于上述新的形态学发现,使用一双孔类(Diapsida)形态特征矩阵重新分析了眼齿鸟的系统演化位置。数据矩阵的分类单元涵盖了蜥蜴、鸟类和鳞龙形类与主龙形类中的主要支系。分析所得的严格合意树明确了眼齿鸟属于鳞龙形类中的有鳞类。因此,宽娅眼齿鸟的正型标本显示了足够丰富的形态学信息,完全能够指示眼齿鸟的系统分类位置应为有鳞类,而不是鸟翼类或非鸟恐龙。     

不同恢复年限老参地土壤养分以及酚酸类代谢物含量差异

人工种植西洋参(Panax quinquefolius)具有很高的经济效益, 但连作障碍已成为其产业可持续发展的限制因子。目前对连作障碍成因的研究尚且不足。该研究以收获西洋参后恢复1、10、20年的老参地(分别记为A1、A10、A20)为研究对象, 以未种植过西洋参的土地为对照(CK), 测定和分析土壤养分及酚酸类代谢物的变化, 以期从养分和化感作用的角度解析可能造成西洋参连作障碍的关键因子。通过常规化学性质测定方法和气相色谱质谱联用(GC-MS)的方法测定土壤养分含量, 采用高效液相色谱法(HPLC)测定土壤中的酚酸类代谢物含量。结果显示, 3组收获西洋参后的老参地的土壤pH均显著降低; A1 25种有机态养分(氨基酸类、糖类和糖醇类物质)的含量显著降低, N-乙酰鸟氨酸、5-氨基戊酸、丝氨酸、亮氨酸、甘油和槐糖等的含量均在所有老参地中显著下降, 经过20年轮作后依然不能恢复到对照水平。同时, 与预期相反, 被认为具有化感自毒作用的酚酸类代谢物在收获西洋参后含量也显著下降, 其中, 香豆酸、原儿茶酸、阿魏酸和苯甲酸的含量在A1中显著低于CK, 但经过10年时间轮作后可以恢复到接近对照水平。另外, p-香豆酸和丁香酸在A1、A10、A20的含量均显著低于CK, 即经过20年轮作依然不能恢复到对照水平; 酚酸类代谢物对西洋参生长的积极意义应被重视。相关性分析显示上述有机态养分含量、pH和酚酸类代谢物含量之间大多数呈显著正相关关系, 表明各土壤特性之间存在密切的交互作用。综上所述, 种植西洋参引起的土壤酸化、有机态养分和酚酸类代谢物含量降低及各因子间的协同作用可能是西洋参连作障碍的关键因素。     

两种贝类养殖环境特征污染物的筛选方法研究

采用Micro Tox Model500发光细菌毒性检测仪,对Cu、Pb、Cd、Hg、As、Cr、Zn、石油类、DDT、甲基对硫磷农药(MP)等10种贝类养殖环境污染物进行发光细菌抑制试验。对己知污染物的浓度与其相对应的发光强度进行回归分析,建立相关方程,求出相对发光度为50%时所对应污染物的浓度,即EC₅₀值,将其定义为相对毒性系数(RT),该值越小,表示污染物毒性越大。结果显示,上述10种污染物的相对毒性(RT)大小顺序为DDT>Hg>Cu=Zn>Cd>Cr>Pb=石油类>MP>As;结合两种贝类对上述污染物的生物富集系数(BCF),以RT/BCF值作为最终绝对毒性大小比较的指标,比值越小,危害影响越大,污染物应优先被选择作为环境特征污染物进行监测。经试验分析,缢蛏和泥蚶的养殖环境特征污染物的优先检测顺序分别为,缢蛏:Hg>Cd>Zn>Cu>As>Cr>Pb(椒江口),Cd>Pb>Cu(舟山海域),Cu>Zn>Cr>Pb(长江口);泥蚶:Cd>Pb>Cu(宁波、舟山海域),Cu>Cd>Pb(温州海域)。     

人NK细胞对同种和异种内皮细胞MHCⅠ类分子的差异识别

以HUVEC和PAEC为靶细胞,人PBNK和NK92为效应细胞,研究了人NK细胞对同种和异种内皮细胞杀伤的差异性;并通过酸处理内皮细胞及抗体封闭MHCⅠ类分子、CD94和KIR(NKB1),研究了MHCⅠ类分子对人NK细胞杀伤HUVEC和PAEC的影响. 结果表明,PBNK和NK92对PAEC的杀伤均大于对HUVEC的杀伤. 酸处理后,两种NK细胞对HUVEC杀伤的增加幅度大于对PAEC的;此外,抗CD94单抗未能改变NK的杀伤效应;KIR(NKB1)封闭使PBNK杀伤HUVEC增加95%,杀伤PAEC仅增加29%. 以上结果提示:NK细胞对异种内皮细胞MHCⅠ类分子的差异识别作用可能是NK细胞杀伤PAEC的主要原因,而KIR很可能是NK杀伤内皮细胞时主要的传递抑制信号的受体.     

Microarchitecture of Body Wall of Extant Cyclostome Ectoprocts

Scanning electron microscope and light microscope studies ofthe body wall in cyclostome stenolaemate ectoprocts show thatthis wall has a distinctive microarchitecture. The microstructuresconsist of a linear series of longitudinal canals in the centralregion. Adjoining regions on either side have laminae of overlappingcalcareous tablets. In some cyclostomes at certain stages ofgrowth, laminae may show a less orderly meshwork pattern nearthe canals. The laminate layers of calcareous tablets are enclosedin an organic matrix and are penetrated by tubuli which passfrom the inner part of the body wall to the canals and alsolink the canals. The canals with organic and mineralized matricesopen into pores in the body wall. This elaborate meshwork andcanal and pore system provide the framework for growth and resorptionof the body wall and facilitate transport of cellular materialsfrom one zooid to another in a colony. Calcification at thedistal part of a colony seems to proceed in a series of stagesaround sites of calcification. The pattern of the body wallof the cyclostome ectoproct does not parallel a molluscan patternof skeletal growth as previously proposed. The hypothesis ofa hypostegal coelom in some cyclostome ectoprocts is rejected.     

New observations on Cucullus Steiner from the Neoproterozoic Doushantuo Formation of Guizhou,South China

Wang, Y & Wang, X. 2011: New observations on Cucullus Steiner from the Neoproterozoic Doushantuo Formation of Guizhou, South China. Lethaia, Vol. 44, pp. 275–286. The Neoproterozoic genus Cucullus is the most abundant and largest organism in the Miaohe biota in China, but has remained poorly understood both in morphology and classification. New material recently obtained from the upper Doushantuo Formation (Ediacaran) of northeastern Guizhou, South China, indicates that Cucullus bears thin organic walls composed of complex spongin fibres forming vertical filaments, which may have given rise to transverse filaments. Filaments, non‐mineralized spongin fibres, which may have served to support body, regularly interweave with each other in a body, and form openings on body sides that may have served as incurrent canals. The top pores may have served as excurrent canals. The overall features, including the organic wall, the complex spongin fibre networks, and the possible canal system of Cucullus, suggest a primitive element of the Demospongea. This benthic organism lived in a low‐energy, calm environment near or below the storm wave‐base with influence of episodic storms. Cucullus’ base nestled into the muddy substrate and its sacciform body floated in seawater. □ Cucullus, Doushantuo Formation, Neoproterozoic, Porifera, South China.     

Morphology of the teleost ampullary organs in marine salmontail catfish Neoarius graeffei (Pisces: Ariidae) with comparative analysis to freshwater and estuarine conspecifics

We hypothesized that due to the relative conductivity of the environment, and to maintain sensory function, ampullary organs of marine Neoarius graeffei would differ morphologically from those described previously for estuarine and freshwater conspecifics. Unlike the ampullary systems of N. graeffei from freshwater and estuarine habitats, the ampullary pores of marine specimens occur in two distinct patterns; numerous pores seemingly randomly scattered on the head and ventro‐lateral regions of the body, and pores arranged in distinctive vertical lines above the lateral line on the dorso‐lateral body of the fish. Light and electron microscopy revealed that the ampullary organs also differed morphologically from estuarine and freshwater specimens in the presence of longer ampullary canals, a hitherto unreported canal wall composition, and in the collagen sheath surrounding both the canal and the ampulla proper within dermal connective tissues. Ampullary pores were wider in marine individuals and opened to the longest ampullary canals reported for this species. The canal wall was lined by cuboidal and squamous epithelial cells. Each ampullary canal opened into a single ampulla proper containing significantly more receptor cells than estuarine and freshwater conspecifics. The distribution of ampullary pores as well as the microstructure of the ampullary organs indicates that the electrosensory system of marine N. graeffei differs from those of estuarine and freshwater specimens in ways that would be expected to maintain the functionality of the system in a highly conductive, fully marine environment, and reveals the remarkable plasticity of this species’ ampullary system in response to habitat conductivity. J. Morphol. 276:1047–1054, 2015. © 2015 Wiley Periodicals, Inc.     

The Sensory Canal Systems of the Living Coelacanth, Latimeria Chalumnae: A New Instalment

Entire sensory canal systems of the coelacanth, Latimeria chalumnae, are described: not only the course of principal canals with their primary and secondary collaterals, but also the course and branches of the pit-line and reticular canals. The number of pores on the left side of the head were found to be 296 in an early (yolksac) embryo, 321 in a late term fetus, 485 in a juvenile, and 2974 in adults. This means that in latimeria most of the lateral-line canal system develop after parturition. Pit lines of the living coelacanth are not rows of superficial neuromasts but canals covered by a thin epidermis like in other sensory canals of the lateral line. These pit-line canals, however, have a very specific structure and branching pattern: the medial dorsal pit-line canal is connected by fine branches on top of the head. The infra-dentary pit-line canal connects via these branches with canals deep inside the bones. Several fine and richly branched canaliculi of unknown function radiate from each quadratojugal pit-line canal. The gular plate pit-line canal has superficially branching arms as well as connections to numerous deeper canals inside the bone. These canals consist of fine branches that in turn lead to and open on the ventral surface of the gular plates as small pores. The system is reminiscent of the reticular (pore) canal system known only from some fossil agnathans and fishes. Thus latimeria combines the reticular system of ancient vertebrates with the lateral-line system of modern fishes. The significance of this gular (possibly electro-sensory) system for feeding by the coelacanth will be discussed.     

Aspects of the circulatory system of Pollicipes polymerus J. B. Sowerby (Cirripedia: Thoracica)

The circulatory system of Pollicipes polymerus exhibits a high degree of organization which precludes it from being referred to as an open system. The system is arbitrarily divided into four parts: (1) the circulation of the peduncle and mantle; (2) the distributive circulation of the body, which provides hemolymph to most of the cephalic gut, to the maxillary gland, and to the cirri; (3) the peripheral circulation which distributes blood from the cirri to the peripheral areas of the thoracic region, to most of the thoracic gut, and from the scutal sinus to the peripheral areas of the cephalic region; and (4) the collecting circulation, which conveys hemolymph mostly from the peripheral circulation of the body to the peduncle. There also may be a circulation that is comparable to the vertebrate lymphatic system. Pumping of hemolymph can be attributed to three pairs of skeletal muscles that compress the dorsolateral channels. These muscles are unique for crustacean muscles in that they do not appear to be striated. The rostral vessel appears to be a vestige of a heart in which the pump muscles have been lost. There is a similarity of the rostral vessel to the heart of Calanus finmarchicus (a copepod). This is additional evidence linking the cirripeds with the copepods within the Maxillopoda. Electron microscope observations of the walls of the midsagittal vessels indicate that there is a more or less random layering of cellular and noncellular elements within the wall. Muscle cells appear to be incorporated in the vessel wall.     

Structure and Composition of the Cell Wall of Neurospora crassa

The structure and composition of the cell walls of hyphae of Neurospora crassa were investigated by electron microscopy, chemical analysis, and X-ray diffraction both before and after progressive enzymatic degradation by snail gut enzymes, chitinase, and trypsin. The wall consists of two phases: randomly disposed skeletal microfibrils of chitin only and an amorphous matrix which contains both beta-glucans and protein. The protein contains a high percentage of the amides of aspartic and glutamic acid but no hydroxy-proline or cysteine. A portion of this protein is a component of or is associated with a system of pores which is embedded in the matrix of the wall. These pores, 40 to 70 A in outside diameter, sometimes branch and seem to provide a three-dimensional network from one side of the wall to the other. They may be a general system of transport across the walls.     

A synthetic medium for continuous culture of the S-layer carrying Bacillus stearothermophilus PV 72 and studies on the influence of growth conditions on cell wall properties

Bacterial cell surface layers (S-layers) which show a crystalline structure, defined pores, and a regular arrangement of functioal groups can be used for production of isoporous ultrafiltration membranes and as a matrix for immobilization of macromolecules. S-layer-carrying cell wall fragments from thermophilic Bacillaceae possess an extremely thin peptidoglycan-containing layer with pores larger than those in the S-layer lattice. Thus, they can directly be used for biotechnological applications, when an S-layer protein pool is stored in the rigid cell wall layer which is released during cell wall preparation, forming an inner S-layer. In the present study, a synthetic medium for Bacillus stearothermophilus PV 72 was developed by applying the pulse and shift technique with the aim to produce cell wall fragments with before-mentioned properties by varying the growth conditions in condtinuous culture. The organism was grown at 57 degrees C in a bioreactor with 1 L working volume equipped with exhaust gas analysis and connected to a PC-based process control system. Biomass concentration was 2.2 g/L out of 8 g/L glucose at a dilution rate of 0.3 h(-1), giving a biomass productivity of 0.66 g/L h. Although the organism was grown under different conditions, no change in peptidoglycan composition, extent of peptidoglycan crosslinking, and content of secondary cell wall polymers was observed. The amount of S-layer protein pool stored in the rigid cell wall layer and the autolytic activity depended mainly on the specific growth rate. Cell wall fragments with properties required for ultrafiltration membrane production could be produced by parameter settings in continuous culture. (c) 1995 John Wiley & Sons, Inc.     

Mechanosensory system of the lateral line in the subantarctic Patagonian blenny Eleginops maclovinus

This study describes the cephalic and trunk lateral line systems in Patagonian blenny Eleginops maclovinus juveniles, providing morphological details for pores, canals and neuromasts. Eleginops maclovinus juveniles possess a complete laterodorsal lateral line that extends from the upper apex of the gill opening along the trunk as far as the caudal fin. The lateral line was ramified through pores and canals. The following pores were recorded: four supraorbital pores, with two along the eye border and two on the snout; seven infraorbital pores, with three on the lacrimal bone and four being infraorbital; five postorbital pores, with three along the preopercular border (upper preoperculum branch) and two on the bone curvature (inferior preoperculum branch); and four mandibular pores aligned along the jaw. Furthermore, five narrow-simple and interconnected canals were found (i.e. preopercular, mandibular, supraorbital and infraorbital canals). Histologically, the dorsal lateral line presented thin neuromasts (350 μm) with short hair cells. By contrast, the cranial region presented long, thick neuromasts. Infraorbital and mandibular neuromasts had a major axis length of 260 μm and respective average diameters of 200 and 185 μm. Sensory system variations would be due to a greater concentration of neuromasts in the cranial region, allowing for a greater perception of changes in water pressure. Scarce morphological information is available for the lateral sensory system in Eleginopsidae, particularly compared to Channichthyidae, Bovichthydae, Artedidraconidae and Bathydraconidae. Therefore, the presented results form a fundamental foundation of knowledge for the lateral-line system in juvenile E. maclovinus and provide a basis for future related research in this taxon as well as within the Notothenioidei suborder.     

Perspectives and challenges of micro/nanoplastics‐induced toxicity with special reference to phytotoxicity

Plastic pollution has become a global concern for ecosystem health and biodiversity conservation. Concentrations of plastics are manifold higher in the terrestrial system than the aquatic one. Micro/nanoplastics (M/NP) have the ability to alter soil enzymatic system, soil properties and also affect soil borne microorganisms and earthworms. Despite, the knowhow regarding modulatory effects of plastics are acquired from the study on aquatic system and reports on their phytotoxic potentials are limited. The presence of cell wall that could restrict M/NP invasion into plant roots might be the putative cause of this limitation. M/NP inhibit plant growth, seed germination and gene expression; and they also induce cytogenotoxicity by aggravating reactive oxygen species generation. Dynamic behavior of cell wall; the pores formed either by cell wall degrading enzymes or by plant–pathogen interactions or by mechanical injury might facilitate the entry of into roots M/NP. This review also provides a possible mechanism of large sized microplastics‐induced phytotoxicity especially for those that cannot pass through cell wall pores. As M/NP affect soil microbial community and soil parameters, it is hypothesized that they could have the potential to affect N₂ fixation and research should be conducted in this direction. Reports on M/NP‐induced toxicity mainly focused only on one polymer type (polystyrene) in spite of the toxicological relevancies of other polymer types like polyethylene, polypropylene etc. So, the assessment of phytotoxic potential of M/NP should be done using other plastic polymers in real environment as they are known to intract with other environmental stressors as well as can alter the the soil–microbe–plant interaction.