Ultrastructural observations on sporogenesis ofMyxobolus Kwangsiensis Hsieh,Gong & Xiao from the kidney of daceLabeo rohita

The early stages and capsulogenetic stages of sporogenesis ofMyxobolus kwangsiensis were studied in detail by electron microscopy.M. kwangsiensis is an intracellular myxosporean infecting the epithelial cells of kidney tubules of young daceLabeo rohita. TheM. kwangsiensis sporogensis presents the typical features of myxosporea. The initial stages are multinucleate primary cells, with one primary cell typically enclosing one secondary cell. The secondary cells are formed directly by cytokinesis inside the primary cells. The primary cell participates in the formation of the secondary cell nucleus. The nuclear division of primary cell is asynchronous by amitosis. The parasitic organisms may degenerate inside the epithelial cells at any stage. The modes of sporoblast formation, the typical features of myxosporea and the cause of its degradation are discussed. This research was supported by the NSFC. (No. 39070675)     

Molecular Characterization,Tissue Distribution and Localization of Larimichthys crocea Kif3a and Kif3b and Expression Analysis of Their Genes During Spermiogenesis

KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis. To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow croaker Larimichthys crocea, we studied the testis characteristics at different developmental stages of L. crocea, and determined the spatiotemporal expression patterns of kif3a and kif3b during spermiogenesis. Quantitative real-time PCR(qR T-PCR) showed that the overall trends of kif3 a/3 b m RNA abundance during testis development are similar. From stage II to stage V, kif3a/3b m RNA abundances first increased and then fell after reaching a peak at stage IV. Interestingly, the m RNA abundances of both genes at stage V were higher than those at stages II and III. In addition, it is worth of noting that kif3 b m RNA abundance was higher than that of kif3a at all stages. Fluorescence in situ hybridization results revealed that kif3a/3b m RNA abundance dynamics were consistent with the migration of mitochondria, the deformation of nucleus, and the formation of tail. The m RNA hybridization signals of both genes first appeared either around the nuclear periphery or on the side of the nuclei, then appeared at one side of nuclei, and finally were mainly on the tail during spermiogenesis. Our findings contributed to better understanding the molecular mechanisms of spermiogenesis in fish; and suggested that KIF3A and KIF3B may participate in the intracellular transport of mitochondria, nuclear deformation, and the formation of tail during the spermiogenesis in L. crocea.     

Development of suspended conchocelis ofPorphyra haitanensis (Bangiales, Rhodophyta)

This Mar. 1993 to Aug. 1994 study on suspended conchocelis ofPorphyra haitanensis showed that there were three patterns for development of vegetative filaments: filaments to filaments by “budding”; filaments to sporangial branchlets by “budding”, or cell swelling. There were also three patterms for sporangial branchlet development: vegetatively propagating, changing into conchospores, or dying. Each developmental stage had one or more different developmental directions between vegetative filaments and sporangial branchlets. Developments from conchosporangial branchlets to conchospores were sequential and irreversible. Although sporangial branchlets formed at 29°C could give rise to filaments, they could not propagate as healthily under the same conditions as those formed at 25°C did. Probably the crucial period of plant cell differentiation is in the late stage of sporangial branchlets. In line with the developmental directions of different stages, the authors regulated the development of conchocelis to get ideal different developmental stages materials to obtain very developmentally homogeneous stages, including filaments and sporangial branchlets. Contribution No 3283 from the Institute of Oceanology, Chinese Academy of Sciences. Study supported by the Climbing Project B PD-B6-4-2 of the State Science and Technology Commission of China.     

IN VITRO STUDY ON CYTOTOXIC EFFECTS OF THE ORGANOPHOSPHOROUS PESTICIDE PROFENOFOS ON THE GILL CELL LINE,FG-9307, OF THE FLOUNDER （PARALICHIHYS OLIVACEUS）

The FG-9307 cell line derived from the gill of flounder Paralichthys olivaceus was used in the present study to determine the acute cytotoxic effects of the organophosphorous pesticide, profenofos. It was found that the cell growth rate was markedly reduced by profenofos at the concentrations of 2.5, 5 and 7.5 mg/L tested; and that the fine structures of the cells were also altered by profenofos, as evidenced by dilation of nuclear membranes and mitochondria cristae, and presence of enlarged lysoscrneswith engulfed organelles and numerous vacuoles in the cytoplama. Probably, mitochondria, the cell ener-gy-generating sites, are the most prcrninent sites of profenofos cytotoxity in the cells. This seems to be the first report of the use of marine fish cell line for evaluation of the acute in vitro cytotoxicity of organophos-phorus pesticide.     

Quantitative comparison of the expression of myogenic regulatory factors in flounder (Paralichthys olivaceus) embryos and adult tissues

MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, Myf5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions of Myf5, yoD, and myogenin at the early stages have a common characteristic: expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.     

Early development of Chondrus ocellatus Holm （Gigartinaceae, Rhodophyta）

1 INTRODUCTION Red algae C. ocellatus lives in temperate zone of coastal area, and inhabits at substrates from high tide to low tide regions. Its life history is composed of three phases: tetrasporophyte, gametophyte and carposporophyte. Chondrus is one o…     

Production of DMS and DMSP in different physiological stages and salinity conditions in two marine algae

Dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) production by Scrippsiella trochoidea and Prorocentrum minimum was investigated to characterize the effects of physiological stage and salinity on DMS and DMSP pools of these two marine phytoplankton species.Axenic laboratory cultures of the two marine algae were tested for DMSP production and its conversion into DMS.The results demonstrated that both algal species could produce DMS,but the average concentration of DMS per cell in S.trochoidea(12.63 fmol/L) was about six times that in P.minimum(2.01 fmol/L).DMS and DMSP concentrations in algal cultures varied significantly at different growth stages,with high release during the late stationary growth phase and the senescent phase.DMS production induced by three salinities(22,28,34) showed that the DMS concentrations per cell in the two algal cultures increased with increasing salinity,which might result from intra-cellular DMSP up-regulation with the change of osmotic stress.Our study specifies the distinctive contributions of different physiological stages of marine phytoplankton on DMSP and DMS production,and clarifies the influence of salinity conditions on the release of DMS and DMSP.As S.trochoidea and P.minimum are harmful algal bloom species with high DMS production,they might play an additional significant role in the sulfur cycle when a red tide occurs.     

Three-dimensional fluorescence characteristics of dissolved organic matter produced by <Emphasis Type="Italic">Prorocentrum donghaiense</Emphasis> Lu

Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrum donghaiense at the exponential growth,stationary and decline stages into <0.45 μm filtrate,100 kDa-0.45 μm,10-100 kDa and 1-10 kDa retentate and <1 kDa ultrafiltrate fractions.The fluorescence properties of different molecular weights of dissolved organic matter(DOM) were measured by excitation-emission matrix spectra.Protein-like and humic-like fluorophores were observed in the DOM produced by P.donghai...     

Developmental expression pattern of calmodulin gene in amphioxus Branchiostoma belcheri tsingtauense

We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus (Branchiostoma belcheri tsingtauense). We cultured and sampled the animals at different developmental stages (eggs and larvae), and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.     

Cell cycles and proliferation patterns in Haematococcus pluvialis

Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation;far less attention has been paid to cell cycles and proliferation patterns.The purpose of this study was to clarify cell cycles and proliferation patterns in H.pluvialis microscopically using a camera and video recorder system.The complicated life history of H.pluvial i s can be divided into two stages:the motile stage and the non-motile stage.All the cells can be classifi ed into forms as follows:motile cell,nonmotile cell,zoospore and aplanospore.The main cell proliferation,both in the motile phase and non-motile phase in H.pluvialis,is by asexual reproduction.Under normal growth conditions,a motile cell usually produces two,sometimes four,and exceptionally eight zoospores.Under unfavorable conditions,the motile cell loses its fl agella and transforms into a non-motile cell,and the non-motile cell usually produces 2,4 or 8 aplanospores,and occasionally 20–32 aplanospores,which further develop into non-motile cells.Under suitable conditions,the non-motile cell is also able to release zoospores.The larger non-motile cells produce more than 16 zoospores,and the smaller ones produce 4 or 8 zoospores.Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the non-motile phase.There is,as yet,no convincing direct evidence for sexual reproduction.     

乌龟红血细胞发生研究

通过对乌龟骨髓、脾脏、肝脏等组织涂片的观察研究 ,发现骨髓是乌龟红细胞主要的造血器官 ;红血细胞的发育过程大致经过三个阶段 ,即原始阶段、幼稚阶段、成熟阶段。着重描述了各阶段红血细胞的形态特征 ,并对乌龟红血细胞的发育及命名等问题作了初步探讨     

Structure and Classification of Haemocytes in the Bivalve Mollusc Meretrix meretrix

Light and electron microscopic studies were carried out in order to characterize haemocytes in the bivalve mollusc Meretrix meretrix. According to nucleus and cytoplasm characters, four types of haemocytes were recognized： agranular haemocytes, lymphoid haemocyte, large granular and small granular haemocytes. Agranular hamocyte is the main cell type, accounting for 75%. It is agranular with rich organelles in cytoplasm, including mitochondria, golgi body and endoplasmic reticulum. Glycogen deposits were usually found in this cell type. The number of lymphoid haemocyte accounts for 1% - 2%. This cell type is agranular and shows a high ratio of nucleus to cytoplasm. A few organelles were found. High electrondense granules with diameters of 0.2 - 0.5μm and rich organelles were found in small granular haemocyte. The proportion of this cell type is about 15%. Rich granules of high electron-dense with diameters of 0.8- 2.4μm were found in large granular haemocyte. The proportion of this cell type is about 10%, and the quantity of organelles is the least.     

Interaction of haematopoietic tissue cultures of the Dublin Bay Prawn, Nephrops norvegicus (L.), with the causal agent of luminous vibriosis Vibrio harveyi

Vibrio harveyi cells (dose—<10³ cells mL⁻¹) and extracellular products (ECP; >25 μmg mL⁻¹ of total protein concentration) destroyed haematopoietic cultures of Nephrops norvegicus within 24 h of exposure. Cytopathic effects (CPE) started after 4h of exposure to the bacterial cells, with some granularity in the cytoplasm, mostly in cells in the outer periphery of the explant growth. At the end of the infection, a considerable number of nuclei remained attached to the substrate, apparently unaffected. Following exposure to ECP, initial deterioration was observed at 2 h with the presence of granularity in the cytoplasm of<20% cells, and few cells displayed small vacuoles around the nuclei. Parallel results were obtained using whole animal experiments, with V. harveyi cells being lethal to nephrops within 24 h.     

Distribution and abundance of eggs and larvae of antarctic krill (Enphausua superba Dana) in antarctic Peninsula area

During the First Chinese Antarctic Expedition zooplankton samples were collected at each of the oceanography stations in the waters around South Sheltland Islands (S.S.Is.) and in the northern part of the Bellinshausen Sea from 20 January to 12 February, 1985 by vertical tows of an 80 cm diameter conical net from 200 m to surface. Two deep tows with a closing net. were performed in slope water north of S.S. Is, and in the basin of Bransfield Strait. Eggs and larvae ofEuphausia superba Dana in zooplankton samples were identified and counted. There were four records of eggs from 27 stations. Most catches were of small number and restricted to within the nearshore area south of S.S. Is. The largest number (1500/1000 cubic meters) was found in the outer side of Smith Island. No Nauplius was found. The earliest stage we found was Metanauplius, in two deep tows. The distribution of Calyptopis I–II and Furcili I–III were quite similar. They were found mainly in three areas: 1) nearshore water along the south coast of S. S. Is.; 2) slope water north of Smith Island; 3) Gerlache Strait. In a station close to the north entrance of Gerlache Strait all the developmental stages from Calyptopis I to Furcilia IV were found. Contribution No. 1600 from the Institute of Oceanology, Academia Sinica.     

以江蓠为栖息环境养殖的双齿围沙蚕性腺发育

研究以江蓠为养殖基质的双齿围沙蚕的配子发生及性腺发育。结果表明:1)根据双齿围沙蚕卵细胞形态特征、内部结构、卵径大小,卵母细胞的发生可划分为第Ⅰ时相(卵原细胞)、第Ⅱ时相(小生长期初级卵母细胞)、第Ⅲ时相(大生长期初级卵母细胞,卵黄形成前期、卵黄形成中期、卵黄形成后期)和第Ⅳ时相(成熟卵母细胞,胶膜形成前期、胶膜形成后期)等4时相;根据各时相卵子的数量变化及体腔中其他结构的形态变化,将雌性性腺分为Ⅰ期卵巢、Ⅱ卵巢、Ⅲ卵巢、Ⅳ卵巢和Ⅴ期卵巢等5个阶段。2)根据双齿围沙蚕体腔内精母细胞的大小、形态和所处的位置,将双齿围沙蚕的精子发生划分为精原细胞、初级精母细胞、次级精母细胞、精细胞和精子;根据各时相精子的形态和数量变化以及体腔中其他组织器官的形态变化,将双齿围沙蚕的雄性性腺划分为Ⅰ期精巢、Ⅱ期精巢、Ⅲ期精巢、Ⅳ期精巢和V期精巢等5个阶段。3)Ⅰ-Ⅳ期的性腺主要包含对应时相的生殖细胞,同时,也存在有少量其他时相的生殖细胞,生殖细胞的发育速度并不完全一致。     

Episodes of volcanic activity and their environmental effects in the Okinawa Trough during the last 150 ka

1 INTRODUCTIONA large-scale volcanic eruption can injectenormous amount of ash and dust into the atmos-phere, leading to local and short cooling due toshielding incoming radiation. During the past 2 to 3decades, accumulated evidence indicated thatlarge-scale volcano eruptions or series of volcanicactivity appears to coincide with climatologicaltransitions. For example, Robock (1979) indicatedthat volcanic eruptions played a role in forcing "Lit-tle Ice Age". Well-dated high-resolution co…     

光温敏核不育水稻幼穗育性转换期蛋白质组的初步分析

为找寻光温敏核不育水稻幼穗与育性调控有关的蛋白质,采用固相pH梯度-SDS聚丙烯酰胺双向凝胶电泳对光温敏核不育水稻(培矮64S)育性转换期幼穗总蛋白进行了分离,获取凝胶图像并进行重复性分析,通过微量测序-Edman降解方法和原位酶解及MALDI-TOF质谱的方法鉴定了60个蛋白质点。结果表明:本方法可得取分辨率和重复性较好的凝胶图谱。蛋白质点在2D胶上的重复性为:沿等电聚焦方向偏差为1.49±0.22 mm,沿SDS-PAGE方向偏差为1.24±0.18 mm。37个蛋白质点得到了准确的鉴定结果,其中16个是差异蛋白质点。在不育变化为可育的过程中,明显表达上调的蛋白质点包括几丁质酶,丙酮酸脱氢酶等;明显下调的蛋白质包括超氧化物歧化酶,硝酸还原酶脱辅基酶蛋白等;金属硫蛋白RicMT只在可育中存在。