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1.
南海沉积物细菌胞外蛋白酶在家族水平上的多样性 总被引：2，自引：0，他引：2
海洋产蛋白酶细菌及其分泌的胞外蛋白酶在降解有机氮以推动海洋氮循环进行方面发挥着重要作用，但目前对这二者多样性的认识非常有限。本研究自南海沉积物中筛选得到90株产蛋白酶细菌，并通过N-端氨基酸序列，分析了其胞外蛋白酶在家族水平上的多样性。16S rRNA基因序列分析的结果表明，筛选的产蛋白酶细菌均属于Gammaproteobacteria纲，且大多数属于Alteromonadales目和Vibrionales目的不同属。对其中14株菌株的14个胞外蛋白酶的N-端氨基酸序列分析表明，所有这些蛋白酶属于金属蛋白酶的M4家族或丝氨酸蛋白酶的S8家族。本研究提供了海洋沉积物产蛋白酶细菌在类群及其胞外蛋白酶在类型上的新细节，这将有助于全面了解微生物酶促降解海洋沉积物有机氮的过程和机理。 相似文献
2.
通过克隆大黄鱼(Larimichthys crocea)的EBI3(Epstein-Barr virus-induced gene 3)基因并对其进行了序列分析.大黄鱼EBI3(Lyc EBI3)基因开放阅读框长747bp,编码248个氨基酸,存在1个信号肽序列和2个FN3结构域(37~130,145~230).多序列比对发现Lyc EBI3分子与其他已知EBI3氨基酸水平一致性为27.68%~57.53%.Real-time PCR结果表明,Lyc EBI3基因在脾脏和血液中表达量最高,且溶藻弧菌(Vibrio alginolyticus)刺激后,大黄鱼头肾和脾脏中Lyc EBI3基因的转录水平会显著升高,说明Lyc EBI3基因可能参与了抑制由细菌引起的炎症反应. 相似文献
3.
白细胞介素10(Interleukin 10,IL-10)是一种抗炎细胞因子,可以抑制机体免疫反应。本研究经过分析大黄鱼基因组数据库发现了IL-10同源基因,并对其cDNA编码区序列和基因组DNA序列进行了克隆分析。大黄鱼IL-10(LycIL-10)基因由5个外显子和4个内含子构成,其序列全长1 869bp,其开放阅读框(ORF)长555bp,编码184个氨基酸,其N端的22个氨基酸残基为预测的信号肽,成熟肽由162个氨基酸残基组成,包含了脊椎动物IL-10标志性保守序列。LycIL-10的氨基酸序列同其他已知物种的IL-10氨基酸序列的一致性为26.49%~77.01%。Real-time PCR分析发现LycIL-10在检测的组织中为组成型表达,在脾脏和肌肉中转录水平相对较高。三联灭活细菌疫苗和聚肌苷酸胞苷酸(poly(I∶C))刺激后,大黄鱼头肾和脾脏中LycIL-10mRNA的转录水平会显著升高,表明LycIL-10可能参与抑制大黄鱼由细菌和病毒引起的炎症反应。 相似文献
4.
engrailed基因属于同源异形基因家族成员,在许多动物的分节、附肢发育、神经系统发育和贝壳形成过程中发挥作用。本研究克隆了长牡蛎两个engrailed同源基因,命名为cgi-eng1和cgi-eng2。序列分析表明,两个基因均具备典型engrailed基因保守的5个EH结构域。利用整装原位杂交技术检测了cgi-eng1和cgi-eng2在贝壳形成的关键时期早期D形幼虫时期的表达情况。结果显示,cgi-eng1和cgi-eng2 m RNA高表达于贝壳外缘,可能与早期贝壳形成过程有关。此外,两个基因的在贝壳外缘的表达模式亦有区别,提示两个基因的功能可能存在一定程度的分化。本研究首次系统鉴定了长牡蛎engrailed基因的成员,并发现它们可能均参与幼虫贝壳形成,研究结果有助于加深对贝类早期发育及贝壳形成的理解。 相似文献
5.
淋巴囊肿病毒是引起多种海、淡水鱼淋巴囊肿病的病原,且不同淋巴囊肿病毒分离株间存在一定的差异。本文对25株淋巴囊肿病毒分离株mcp基因的变异特征进行分析,结果表明:分离自同一宿主的淋巴囊肿病毒mcp基因序列并非完全一致,有些同宿主分离株间存在着较少的变异,其MCP蛋白序列间的变异位点多位于不规则结构域、属于非蛋白相互作用位点;分属不同基因型淋巴囊肿病毒分离株MCP蛋白序列间的变异位点也多位于不规则结构域,变异位点为蛋白相互作用位点的比率仅占21.98%。金头鲷淋巴囊肿病毒分离株LCDV-sa是一种新的淋巴囊肿病毒基因型,此25株淋巴囊肿病毒可分为7个基因型。对淋巴囊肿病毒变异的研究,可加深对其感染机制的认识,有助于了解其传播途径,可为淋巴囊肿病的防控提供重要的理论依据。 相似文献
6.
细菌通过趋化系统感知和响应外界环境变化并进行趋利避害, 因此很多细菌进化出了非常复杂多样的趋化系统以适应不同的生态位。Epsilon-变形菌广泛存在于自然界中, 能适应不同的生态环境, 特别是深海Epsilon-变形菌能适应深海热液口和冷泉等极端环境, 其趋化系统可能有其独特之处。通过BlastP和MIST数据库分析, 我们发现大部分深海Epsilon-变形菌拥有F3类型趋化系统且具有单拷贝的双功能域融合蛋白CheV。此外, 一种特殊结构域CZB (C-terminal Zinc-Binding) 存在于深海Epsilon-变形菌的趋化受体蛋白中, 而且在部分深海Epsilon-变形菌的趋化受体中还发现并鉴定了一种新的结构域CZB-like结构域。文章以Epsilon-变形菌的模式菌株空肠弯曲杆菌(Campylobacter jejuni 81-176)为研究对象, 用细菌双杂交试验证实了CheV能与所有含MA结构域的趋化受体相互作用。用电感耦合等离子体质谱(ICP-Mass)技术证实了CZB-like结构域不能结合Zn离子, 但细菌双杂交试验证实它能介导趋化受体Tlp9与CheV的互作。 相似文献
7.
《海洋学研究》2016,(4)
以源于东太平洋海水的4株红球菌分离菌Rhodococcussp.EPR-134、Rhodococcus sp.EPR-147、Rhodococcus sp.EPR-157和Rhodococcus sp.EPR-279为研究对象,开展了菌株的色素提取和色素全波长扫描,并基于全基因组测序分析了4株细菌类胡萝卜素代谢通路中的相关基因。色素全波长扫描结果显示,菌株EPR-134不具备类胡萝卜素产生能力,而其它3株红球菌能够产生类胡萝卜素,且所产类胡萝卜素组分不同。基因组分析表明,4个细菌基因组中存在较为完整的促使类胡萝卜素形成的基因簇。对菌株参与番茄红素形成的3个关键基因crt E、crt B和crt I的氨基酸序列同源性两两比对分析表明,菌株EPR-134 3个基因氨基酸序列与其它3个菌株相应基因氨基酸序列同源性最低,这可能是导致该菌株不产类胡萝卜素的关键原因。该研究结果为产类胡萝卜素红球菌的遗传改造,以及为产类胡萝卜素工程菌的构建奠定了前期基础。 相似文献
8.
首次在瘤背石磺(Onchidium struma)中克隆得到一种新的表皮生长因子(EGF)的cDNA序列全长。EGF基因cDNA的全长为1158bp,命名为Os-egf1,其中开放阅读框长度为846 bp,编码一条包含281个氨基酸残基的多肽链。根据氨基酸序列比对和结构域分析结果发现其含有2个保守的EGF结构域和1个EGF-like结构域,每个结构域中均包含至少6个半胱氨酸残基,且形成CX7 CX4-5 CX10-13CXCX8 C结构,其结构域由C1~C3、C2~C4和C5~C6之间形成的3个二硫键维持,符合表皮生长因子家族及其相关蛋白的特征结构域,但其余氨基酸序列与现有相关基因差异较大,推测可能是一种新的EGF-like基因。利用MEGA6.0软件构建Os-egf1与EGF家族相关蛋白的系统进化树,表明EGF家族蛋白具有一定的物种特异性。 相似文献
9.
利用cDNA末端快速克隆(RACE)技术,获得海带(Saccharina japonica) CRY-DASH基因(SjCRYDASH)全长序列,结构分析发现,其ORF区长1779 bp,编码592个氨基酸。进行氨基酸同源序列比对,其与其他藻类和高等植物间存在两个重要辅基MTHF和FAD结合的保守域。通过不同光质照射诱导海带幼孢子体,发现蓝光、白光诱导1h后,均能使SjCRY-DASH转录水平上升,且SjCRY-DASH对蓝光的响应更强烈。本研究结果为研究大型褐藻-海带CRY-DASH受光诱导调控功能打下基础。 相似文献
10.
从龙须菜鲁龙1号、981品系不同发育阶段转录组数据中,挑选差异表达显著基因——hsp、gln,对其上游与全基因序列测序分析。Hsp中8个保守位点均处HSP20结构域内。Gln具谷氨酰胺合成酶N结构域和龙须菜特有的两个跨膜区与低复杂性区域。2个基因表达均可能受缺氧、光照、茉莉酸甲酯等环境及植物激素调控影响。利用荧光定量技术发现不同品系龙须菜的发育过程中hsp与gln表达水平的变化趋势相似。hsp表达水平在Ⅰ到Ⅲ阶段缓慢上升,在Ⅳ阶段大幅升高,这可能与藻体表面伤口的修复相关。gln表达水平在Ⅰ到Ⅱ阶段上升,在Ⅱ到Ⅳ阶段下降,于Ⅳ阶段最低,gln可能与四分孢子囊形成相关。在龙须菜不同品系中2基因表达水平存在差异,这可能与两品系不同的育性表现相关。 相似文献
11.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
12.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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15.
《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance. 相似文献
17.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
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This study tests the hypothesis that the in situ void ratio of surficial marine sediments may be predicted from shear wave velocity-depth data with a reliability equal to that of other methods currently available. Shear wave velocity is fundamentally controlled by the number of grain-to-grain contacts per unit volume of material and by the effective stress across those contacts. In this study, three previously established empirical formulae are used to predict void ratio from velocity-depth data. Field data were acquired along a transect off the northern Californian coast across which water depth increased from 35 to 70 m and seafloor sediment type varied from sand to silty-sand, respectively. A towed seafloor sled device was used to collect shear wave refraction data, and a marked, systematic decrease in velocity was observed along the line, ranging from 35-70 m/s for the coarse, near-shore material to 25-40 m/s for the finer, offshore deposits. Void ratios predicted from these velocities were compared with data measured directly from box-core samples. Of the formulae used for prediction, two agree remarkably well with the control data. Both predicted and control values increase from 0.6-0.8 for the sandy material to 1.1-1.5 for the silty-sand. Thus, this study does not disprove the hypothesis set and demonstrates the potential of field shear wave velocity-depth data as a means of delineating spatial variation in void ratio for surficial marine sediments in a remote, nondestructive manner. 相似文献
20.
Hoi-Soo Jung Kap-Sik Jeong Yong-Shik Chu Sung-Hyun Park Ki-Hyune Kim 《Marine Georesources & Geotechnology》2001,19(3):181-195
Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors. 相似文献