Ontogenetic Development of the Caudal Neurosecretory System in the Chum Salmon, Oncorhynchus keta, with Regard to Its Ultrastructural Changes and with Relation to Neuropeptide Y-immunoreactive Fibers

The ontogeny of the caudal neurosecretory cells (Dahlgren cells) in the caudal spinal cord of the chum salmon, Oncorhynchus keta, was examined by conventional electron microscopy and with immunohistochemistry for urotensins (U) and neuropeptide Y (NPY). The precursors of the Dahlgren cells first appeared as agranular ovoid cells in the caudal region of the neural tube of 40-day-old embryos about one week before hatching. The occurrence of cytoplasmic granules in the immature Dahlgren cells became evident by the 14th day after hatching. At this moment, the U-positive reaction was merely demonstrated in some of the granules. Close association of NPY-positive fibers with the caudal neurosecretory structures was recognizable in 1-month-old larvae. Thus, it is apparent that the salmon Dahlgren cells start their secretory activity (production of the secretory granules) in early larval stages and that, thereafter, NPYergic afferent innervation of the caudal neurosecretory system becomes evident.     

Increasing the hydrolysis constant of the reactive site upon introduction of an engineered Cys14?Cys39 bond into the ovomucoid third domain from silver pheasant

P14C/N39C is the disulfide variant of the ovomucoid third domain from silver pheasant (OMSVP3) introducing an engineered Cys¹⁴? Cys³⁹ bond near the reactive site on the basis of the sequence homology between OMSVP3 and ascidian trypsin inhibitor. This variant exhibits a narrower inhibitory specificity. We have examined the effects of introducing a Cys¹⁴? Cys³⁹ bond into the flexible N‐terminal loop of OMSVP3 on the thermodynamics of the reactive site peptide bond hydrolysis, as well as the thermal stability of reactive site intact inhibitors. P14C/N39C can be selectively cleaved by Streptomyces griseus protease B at the reactive site of OMSVP3 to form a reactive site modified inhibitor. The conversion rate of intact to modified P14C/N39C is much faster than that for wild type under any pH condition. The pH‐independent hydrolysis constant (K_hyd°) is estimated to be approximately 5.5 for P14C/N39C, which is higher than the value of 1.6 for natural OMSVP3. The reactive site modified form of P14C/N39C is thermodynamically more stable than the intact one. Thermal denaturation experiments using intact inhibitors show that the temperature at the midpoint of unfolding at pH 2.0 is 59 °C for P14C/N39C and 58 °C for wild type. There have been no examples, except P14C/N39C, where introducing an engineered disulfide causes a significant increase in K_hyd°, but has no effect on the thermal stability. The site‐specific disulfide introduction into the flexible N‐terminal loop of natural Kazal‐type inhibitors would be useful to further characterize the thermodynamics of the reactive site peptide bond hydrolysis. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

Introduction and Notes to R. Dahlgren's System of Classification of the Angiosperms

The present paper aims at introducting Dahlgren’s system of classification of the angiosperms. Phenetic and phylogenetic classifications are discussed. The basic principles and methods used by Dahlgren are explained. Dahlgren’s opinions on some important problems, such as the origin of angiosperms, the flowers of primitive angiosperms, the relation between the dicotyledons and monocotyledons, the origin of the monocotyledons, the treatment of the “Amentiferae” and of the orders of the “Sympetalae”, are all expressed. A brief comparison between Dahlgren’s system and three other current systems, viz. those of Takhtajan, Cronquist and Thorne is also given.     

塔克尔莫乎尔沙漠银沙槐群落主要植物的种间关系

根据野外调查的样地数据资料,运用2×2列联表的Fisher精确检验、Pearson相关系数和Spearman秩相关系数检验,并结合DCA排序,分析塔克尔莫乎尔沙漠银沙槐群落主要植物种群之间的种间关系。结果表明:Fisher精确检验有3个种对呈显著正关联,3个种对呈显著负关联;Pearson相关系数检验有1个种对呈显著正相关,12个种对呈显著负相关;Spearman秩相关系数检验,有14个种对存在显著相关,其中负相关13对,占所有种对数的14.29%,正相关1对,占所有种对数的1.1%。银沙槐群落种间关系相对松散,反映出植物群落随着环境变化其物种组成也发生相应变化,正向着相对稳定独立的无关联方向发展。     

NEW RECORDS OF ASCOPHYLLUM NODOSUM (L.) LE JOL. FROM THE WARMER PARTS OF THE ATLANTIC OCEAN1

Floating plants of Ascophyllum nodosum (L.) Le Jol. have been found for the first time at 00°47'S, 14°10'W to 01°21'S, 13°32'W. Populations of attached individuals do not occur below 40°N, although previous records of drift plants are known from further south. The plants found near the equator have probably arisen from attached populations in western Europe.     

A histoenzymological investigation of the caudal neurosecretory system in six species of freshwater teleosts: a comparative study

Enzymecytochemical features of the caudal neurosecretory system of 6 species of freshwater teleosts, Gudusia chapra, Gonialosa manmina (Clupeidae, Clupeiformes), Oxygaster bacaila (Cyprinidae, Cypriniformes), Mystus bleekeri (Bagridae, Cypriniformes), Sciaena coiter (Scienidae, Perciformes), and Mastacembelus pancalus (Mastacembelidae, Mastacembeliformes) have been investigated with the help of several specific histochemical techniques. No sex-dependent variation have been observed in the enzymecytochemical characteristics of the caudal neurosecretory system of the present species. The Dahlgren cells show intense RNA activity. Caudal neurosecretion lacks carbohydrate but seems to possess small amount of lipid. Acid-phosphatase is located in the Dahlgren cells and axons. Alkaline-phosphatase has been observed in the Dahlgren cells, axons, and urophysial blood-capillaries. Acetylcholine esterase is present in the Dahlgren cells, axons, and urophysis of Mystus, Mastacembelus, and Gonialosa, but lacking in the other 3 species. It is concluded that the caudal neurosecretory system of Mystus, Mastacembelus, and Gopialosa is innervated by cholinergic neurons. Despite their different taxonomic positions, caudal neurosecretory system of all 6 species produce similar responses to various enzymecytochemical tests, except for acetylcholine esterase.     

Length‐weight relationships of seven fish species from Amazonian Equatorial coast,Brazil

Parameters of the length‐weight relationship (LWR) were estimated for seven fish species from Amazonian Equatorial coast of Maranhão, Brazil. Samplings were carried out in three sample points of the lower stretch of the Itapecuru River (2°57'6.2"S and 44°14'26.5"W; 3°0'33.0"S and 44°15'54.7"W; 3°3'42.9"S and 44°15'1"W). The specimens were caught quarterly from June 2012 to August 2014 using monofilament gillnets (10, 20, 30, 40, 50, 60, 70 and 80 mm between knots) from 10 m to 30 m long and 4 m to 6 m high. This study provides the LWR parameters for Schizodon dissimilis, Curimata macrops, Prochilodus lacustris, Geophagus surinamensis, Hassar affinis, Platydoras brachylecis and Hypostomus plecostomus.     

椿根皮的化学成分及抑菌活性研究

为探寻椿根皮抑菌的物质基础，该研究采用硅胶、Sephadex LH-20等方法对椿根皮甲醇提取物进行分离和纯化，通过理化性质和波谱数据分析单体化合物的结构，并以卡那霉素为对照组采用流式细胞法测试化合物的抑菌活性。结果表明：从椿根皮中得到22个化合物，分别鉴定为pleuchiol (1)、withastramonolide (2)、7-ketositosterol (3)、白桦酯醇(4)、桦木酸甲酯(5)、1, 2, 4-trimethoxybenzene (6)、顺丁烯二酸二甲酯(7)、sonderianol (8)、dibutyl phthalate (9)、pinoresinol (10)、对羟基苯甲酸乙酯(11)、avenalumic acid methyl ester (12)、5,3′-dihydroxy-3,7,4′-trimethoxy-flavone (13)、spathulenol (14)、2-甲基-5-丙基酮-7-羟基色原酮(15)、 7,4′-dihydroxyflavone (16)、annphenone (17)、3-羟基-4-甲氧基苯甲酸(18)、5,3′...     

黑龙江省不同纬度梯度农田大型土壤动物群落分布特征

沿着由高到低的纬度梯度,分别在塔河、带岭、帽儿山的农田生境选择研究样地,采用手捡法调查不同纬度农田生态系统大型土壤动物的群落组成、水平结构、垂直结构和多样性特征,并运用双变量相关分析及典范对应分析阐明土壤动物群落和环境因子的相互关系,旨在揭示黑龙江省不同纬度梯度农田大型土壤动物群落分布特征及其影响因素。调查共捕获大型土壤动物35类2339只,隶属于2门6纲14目35科。其中线蚓科(Enchytraeidae)、正蚓科(Lumbricidae)、步甲科(Carabida)、隐翅虫科(Staphylinidae)为优势类群,其个体数占总个体数的58.84%;常见类群为蚁科(Formicidae)、蜘蛛目(Araneida)和地蜈蚣目(Geophilomorpha)等8类,其个体数占总个体数的32.79%。结果表明:(1)水平分布上:大型土壤动物个体密度和丰富度(即类群数)的水平分布均表现为帽儿山带岭塔河,单因素方差分析表明大型土壤动物的个体密度和丰富度在不同纬度地区无显著差异。Shannon-wiener多样性指数(H')和Pielou均匀度指数(E)均为帽儿山带岭塔河;Simpson优势度指数(C)表现为塔河和带岭最高,帽儿山最少;Margalef丰富度指数(D)则是塔河最多,其次为帽儿山和带岭。(2)垂直分布上:3个不同纬度样地的农田土壤动物个体密度和丰富度在同垂直层次间不存在明显差异(P0.05)。除帽儿山5—10 cm土层土壤动物类群数量较表层增加之外,其他样地大型土壤动物个体密度和丰富度均随土层深度的增加而逐渐降低,表聚性明显。(3)与土壤环境因子关系上:双变量相关分析表明,不同纬度农田大型土壤动物的类群数、个体密度、多样性指数、均匀度指数和优势度指数与土壤p H值、有机质、全氮、全磷和速效磷均没有显著的相关性;典范对应分析(CCA)进一步表明,优势类群和常见类群对环境因子具有较强的适应能力,广泛的分布在3个样地内。研究表明,农田生态系统大型土壤动物的类群数、个体密度和多样性指数随纬度梯度的增加先增加后减少,但不同纬度间均无显著性差异。不同土壤动物类群受到环境变量的影响程度不同,在局地尺度环境因子对土壤动物的影响不容忽视。研究为区域尺度农田生态系统土壤动物空间格局和生物多样性维持机制研究奠定基础。     

Cortisol and prolactin modulation of caudal neurosecretory system activity in the euryhaline flounder Platichthys flesus

Previous studies have shown roles for cortisol and prolactin in osmoregulatory adaptation to seawater and freshwater, respectively, in euryhaline fish. This study of the European flounder investigated the potential for these hormones to modulate activity of the caudal neurosecretory system (CNSS), which is thought to be involved in physiological adaptation to changing external salinity. Superfusion of isolated CNSS with either cortisol or prolactin (10 microM; 15 min) led to changes in firing activity in neuroendocrine Dahlgren cells, recorded extracellularly. Cortisol evoked a modest increase in overall firing activity, with the response delayed by 4 h after treatment. The response to prolactin was short latency, continued to build up over the subsequent 4-h wash period, and comprised increased firing activity together with recruitment of previously silent Dahlgren cells. Immunoreactivity for glucocorticoid and prolactin receptors was localised to Dahlgren cells. The CNSS expression level for glucocorticoid-2 receptor mRNA, measured by Q-PCR, was significantly lower in fish fully acclimated to freshwater, compared to seawater. No differences were seen between these two states for prolactin receptor mRNA expression. These results provide evidence for a modulatory action of both hormones on the neurosecretory function of the CNSS.     

Lycopodium Alkaloids from Huperzia serrata and Their Anti-acetylcholinesterase Activities

One new fawcettimine-type alkaloid ( 1 ), one new miscellaneous-type alkaloid ( 2 ), four new lycodine-type alkaloids ( 3 – 6 ), and eight known ones ( 7 – 14 ) were isolated from the whole plants of Huperzia serrata. Their structures and absolute configurations were elucidated based on spectroscopic data, X-ray diffraction, ECD calculation and Mosher's method. Compound 1 was a rare C₁₈N₂-type Lycopodium alkaloid, possessing serratinine skeleton with an amide side chain in C-5. The absolute configuration of the 18-OH of compounds 4 – 6 were first determined by Mosher's method. Moreover, compounds 1 – 14 were assayed anti-acetylcholinesterase effect in vitro, and compound 7 showed significant anti-acetylcholinesterase activity with an IC₅₀ value of 16.18±1.64 μM.     

基于线粒体控制区的嘉陵裸裂尻鱼种群遗传结构分析

嘉陵裸裂尻鱼为青藏高原特有鱼类,近年来随自然地理气候的变迁和人类活动的影响,种群数量急剧减少。为了解嘉陵裸裂尻鱼的遗传背景以便更好的保护其遗传资源,本研究采用线粒体控制区部分序列变异,分析了嘉陵裸裂尻鱼6个地理种群的遗传结构和分布动态。在147尾个体中共发现17个变异位点,定义了14种单倍型,群体总的单倍型多样性较高为0.810,核苷酸多样性低为0.00698。AMOVA分析显示,44.29%的分子差异源于群体间,55.71%的分子差异源于群体内,群体间遗传分化极显著。Fst值统计检验表明,除宕昌群体和舟曲群体之间差异不显著外,其余两两群体之间Fst值统计检验均显著。基因流估计显示各群体间的基因流水平较高,遗传交流较频繁。Mantel test检验表明,嘉陵裸裂尻鱼种群之间遗传分化程度与地理距离存在显著相关。系统树和单倍型网络进化图显示,6个地理群体的单倍型按照嘉陵江水系和渭河水系形成两个大的类群。错配分布和中性检验表明嘉陵裸裂尻鱼群体在近期历史上群体大小保持稳定,未出现显著的种群扩张。根据本文所揭示的嘉陵裸裂尻鱼种群遗传结构特征,建议将分布在嘉陵江水系的嘉陵裸裂尻鱼作为一个整体进行保护,嘉陵裸裂尻鱼渭河种群属高度分化的单倍型类群,且遗传多样性极低,需对该种群进行优先保护。     

六个品种花椰菜花球的营养成分分析与评价

为评价花椰菜(Brassica oleracea var. botrytis)的营养品质,测定了6个品种花球的10项营养指标,运用主成分分析和聚类分析方法对花椰菜品质进行综合评价。结果表明,6个品种的10项品质指标均存在不同程度的差异,变异幅度为12.22%~ 131.21%。维生素C (Vc)、总黄酮、总多酚、Fe、Ca、P、蛋白质含量间存在显著或极显著的关联性。系统聚类分析将6种花椰菜分为4类,黄色花椰菜‘209’、‘100’和‘217’各为1类,白色花椰菜‘210’、‘214’和‘218’聚为1类。主成分分析提取了花椰菜品质综合评价的3个主成分,获得6个营养评价指标：Vc、总黄酮、总多酚、Fe、Ca和P。通过建立评价函数模型: F= 0.5591Z₁+0.2189Z₂+0.1669Z₃,筛选出‘209’花椰菜的营养品质最高。这为挖掘及选育优良花椰菜品种提供了科学依据。     

Locomotor Activity Patterns in Ilybius fenestratus (Fabricius) (Coleoptera,Dytiscidae) in a Central Norwegian Lake,with Evidence for Breeding-Induced Arrhythmicity

The diel activity of Ilybius fenestratus was studied in Målsj?en, a lake in S?r-Tr?ndelag, Central Norway (63°14'N, 10°26'E), during 1971–1972. Adults and larvae were sampled in activity traps every week during March–October and every 2–3 weeks during November–February. The traps were emptied every 2 hrs during a 24- hr period. The diel locomotor activity of I. fenestratus was clearly nocturnal, except in the second half of July, for the males also in the first half of July, when surprisingly the population showed an arrhythmic activity pattern. The arrhythmicity is connected with the mating and egg-laying period of the species. The larvae were also nocturnal in the autumn, but showed arrhythmicity under the ice during the winter.     

渤海东部海域秋季底层游泳动物种类组成及群落多样性

根据2014年9月在渤海东部海域(37°40'—38°20'N、120°00'—121°20'E)进行的游泳动物底拖网调查数据,应用相对重要性指数、生物多样性指数、群落结构多元统计分析等方法对该海域游泳动物种类组成及群落多样性特征进行了分析。结果表明:调查海域共捕获游泳动物54种,以头足类枪乌贼(Loliolus spp.)为绝对优势种;游泳动物资源密度为28.82kg/h和5166尾/h。游泳动物种类Margalef丰富度指数(D)的变化范围为1.99—3.67,Shannon-Wiener多样性指数(H')变化范围为0.89—2.28,Pielou均匀度指数(J')变化范围为0.29—0.69。群落结构多元统计分析表明,渤海东部海域游泳动物群落结构以60%的相似性可划分为3个组群:长岛群岛海域组群(A组群)、龙口海域组群(B组群)和蓬莱海域组群(C组群);ANOSIM分析表明,组群之间差异极显著,两两之间差异亦极显著。受增殖放流影响,C组群资源密度和种类多样性均保持较高的水平,而A、B组群人为活动频繁,过度捕捞严重,对海域生态环境和渔业资源整体结构的破坏较大。     

BIOLOGY OF THE GREEN LACEWING (CHRYSOPA PHYLLOCHROMA). 1: EFFECTIVE ACCUMULATED HEAT AND DEVELOPMENT RATE*

Abstract Two methods were used to estimate the effective accumulated heat (K) and threshold development temperature (To) of the green lacewing, Chrysopa phyllochroma Wesmael, under 7 constant temperatures. The results were as follows: 1) by means of Li Chao's ‘optimum seeking method’, T₀ of eggs, larvae, and pupae are 14. 20, 11. 55 and 8. 27°C respectively, K of them are 53. 82, 151. 58 and 243. 85 day-degrees respectively; 2) by means of Li Dianmo's ‘rapid estimation method’, T₀ of eggs, larvae, and pupae are 14. 33, 12.18 and 8. 38°C respectively, K of them are 54. 41. 157. 62 and 245. 21 day-degrees respectively; 3) based on linear regression equation and the logistic curve equation, the formula for estimating development rates of different development stages at certain temperatures has been established.     

Life History of Ilybius fenestratus (Fabricius) (Coleoptera,Dytiscidae) in a Central Norwegian Lake

The life history of Ilybius fenestratus was studied in Målsj?en, a lake in S?r-Tr?ndelag, Central Norway (63°14'N, 10°26'E), during 1971–1972. Adults and larvae were sampled in activity traps every week during March–October and every 2–3 weeks during November–February. Newly-emerged adults were generally found from mid-July to September, and after overwintering in torpidity, probably in the water, they again appeared in the second half of June to August/September. Laying of eggs took place from early/mid July to early August. Larvae occurred in the traps from late July to early May. I. fenestratus was thus found to be a semivoltine summer breeder, with overwintering larvae the first winter and overwintering adults the next. Both adults and larvae lived in large areas of the lake's littoral zone.