共查询到18条相似文献，搜索用时 250 毫秒
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对海盘车腕再生过程的研究，对于早日揭示棘皮动物等后口动物的再生机理具有重要意义。为了查清棘皮动物的再生方式及其机理，文中利用断腕创伤手术、组织化学和细胞化学技术对罗氏海盘车腕的再生过程进行了研究。连续跟踪研究结果表明，创伤8d后，在罗氏海盘车创伤腕的外表皮层和体腔上皮中均出现了干细胞原基样结构(blastema-like structure)。创伤腕的伤口愈合过程是1个多事件同期发生的综合过程，首先是真皮层中脱分化的肌肉样细胞向创伤处迁移和聚集，经再分化和组织重排逐渐形成成熟的真皮层组织，然后是外表皮层和体腔上皮中的脱分化细胞向创伤处迁移分别形成明显加厚的前表皮层和前体腔上皮，最后再分别分化为成熟的表皮层和体腔上皮。而海盘车腕的再生过程则包括新生腕芽的延长和残腕的延长2个事件同期发生的过程。新生腕芽的生长与延长是在创伤愈合的基础上，依靠表皮层、体腔上皮和真皮层来源的脱分化细胞的迁移和再分化先形成新生腕芽，随后在新生腕芽上又出现了新的干细胞原基样结构，使腕芽逐渐生长和延长。而创伤刺激下残腕的延长，则是在形成干细胞原基样结构的基础上，在残腔体壁的许多部位形成多个横跨体壁的“楔状”干细胞原基样结构，这些结构的多点插入及其再分化形成新的体壁组织使残腕得以延长。本文的研究结果还显示，罗氏海盘车腕的再生同时采用了表变态再生和变形再生2种方式。 相似文献
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海星皂甙及其他活性成分研究概况 总被引：5，自引：0，他引：5
海星又名海盘车 ,属棘皮动物门（Ｅｃｈｉｎｏｄｅｒｍａｔａ） ,海星纲（Ａｓｔｅｒｏｉｄｅａ）。包括显带目（Ｐｈａｎｅｒｏｚｏｎｉａ） ,有棘目（Ｓｐｉｎｕｌｏｓａ） ,钳棘目（Ｆｏｒｃｉｐｕｌａｔａ）等。海星为海生底栖动物 ,在世界各海域均有分布。我国沿海有１００多种 ,黄、渤海常见种类有多棘海盘车、罗氏海盘车、陶氏太阳海星等。海星为肉食性动物 ,吞食各种软体动物、棘皮动物等 ,日吞食量很大。另外 ,海星的繁殖能力和再生能力很强 ,对沿海扇贝、牡蛎、贻贝、鲍鱼等贝类养殖业具有较大危害。近年来 ,有关海星活性成分的研… 相似文献
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研究论述了隐虾亚科这一珊瑚礁环境中引人注目的甲壳动物类群与软体动物、海鞘动物、棘皮动物、腔肠动物和海绵动物等海洋无脊椎动物类群之间的共栖关系,并得出此亚科种类的共栖宿主以腔肠动物最多,其余以次为棘皮动物、海绵动物、双壳类软体动物和海鞘类被囊动物,以及每一种隐虾多以某一目的动物为宿主,宿主跨目者很少,跨纲者更少的结论。为该亚科的分类和进化以及珊瑚礁生态学研究提供了重要基础资料。 相似文献
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神经肽是神经系统最大、最多样化的一类信息分子,可调节动物的各种生理过程和行为。相较于脊椎动物和原口无脊椎动物,棘皮动物神经肽的研究起步较晚,而棘皮动物关键的分类地位和独特的生物学特征为其神经肽信号系统功能的研究提供了特殊背景。本文从神经肽分子的自身特性出发,对棘皮动物神经肽的作用方式、鉴定方法、功能调节及受体发掘等相关研究成果进行了综述,并对其未来的研究进行了展望。以期进一步解析神经肽在棘皮动物特殊生理行为调控中的作用机制,为棘皮动物中经济物种的高效绿色增养殖提供理论支撑。 相似文献
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本实验对安朵仙水母(Cassiopeia andromeda)水母体进行不同程度（伞体、胃囊、口腕和触手）的切割,进行60日再生过程观察。本研究首次记录了安朵仙水母水母体的再生情况：切除部分伞体、全部胃囊、全部口腕和触手的水母体残体能够再生出缺失的部分;切除全部伞体的水母体残体无法再生出新的伞体,而是反向再生出新的口腕和触手;同时切除不同部位的水母体残体在组织修复时表现出一定的再生顺序性。本研究发现安朵仙水母水母体具有较强的组织再生能力,可作为钵水母纲再生研究的潜在模式物种,同时为刺胞动物研究以及再生生物学研究提供一定借鉴。 相似文献
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再生是生物体丢失的组织或器官重新生长和修复的过程,是生物科学的本质问题之一。再生现象在生物界中广为分布,但不同生物的再生能力却存在着巨大差异。虽然近年来再生的分子和细胞机制取得了显著的研究进展,但驱动物种再生能力多样性形成的遗传机制尚不明确。海洋多毛类因其多样且快速演化的再生能力和简单线性的分节结构成为研究再生演化的极佳类群。本文首先从生态和演化生物学的角度综合分析了多毛类再生的特点、进一步总结细胞和分子来源以及再生性状多样性,然后分析了印太交汇区的海洋多毛类再生性状的特点以及外在多圈层因素对再生性状的潜在驱动效应,并就未来的发展趋势提出了建议。 相似文献
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本文提出了一种新型的多波长全光再生方案,利用相位时钟光纤光参量放大,并采用相邻信道偏振正交的方法,实现对由异步信源产生的双波长信号全光再生.理论分析了参量放大中的增益饱和现象用于幅度噪声抑制,以及利用相位时钟及后续色散实现对信号定时的机理.在这个基础上,对两个独立信源产生的异步双波长10 Gbit/s信号进行再生实验,实验表明该方案有效的抑制了基于多波长3R再生系统中信道间的四波混频与交叉相位调制等非线性干扰.系统在单波长和双波长情况下分别将两路信号信噪比改善了至少6.5 dB与4.5 dB.误码率测试结 相似文献
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The regeneration of pore water nutrients was studied and the contribution of benthic nutrient fluxes to the overlying water
was evaluated on the basis of field specific observations conducted in September–October 1998 and April–May 1999 in the Bohai
Sea. Nutrient concentrations in sediment pore waters were examined by incubating sediment core samples with overlying seawater
in air and/or nitrogen conditions. Nutrient diffusion fluxes calculated by diagenetic equations were within a factor of 2
during incubations. The factors affecting nutrient diffusion across sediment/water interface include bioturbation, nitrification,
denitrification, adsorption, and dissolution. The regeneration of nutrients from sediments will increase nutrient loads of
the Bohai Sea and affect nutrient atomic ratios in this region. Among nutrient sources from riverine input, atmospheric deposition
and sediment regeneration, ammonium and phosphate mainly came from atmospheric deposition (>50%); nitrate was mainly transported
by riverine input into the Sea, silicate from sediment regeneration accounts up to 60%. This demonstrates that nutrient regeneration
in sediments contributes more silicate than riverine input and atmospheric deposition together, but benthic flux contributes
very much less phosphate and nitrate relative to riverine input and atmospheric deposition. The benthic fluxes of nutrients
may lead to a decrease of the amount of nitrate, an increase of phosphate, ammonia and silicate in the water column. The release
of silicate from sediments may compensate the decrease of silicate due to the reduction of riverine discharge. Nutrient regeneration
in sediment may have an important influence on the eutrophic character of coastal waters in this region.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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二次生烃机理在中下扬子高演化烃源岩评价中的应用 总被引：1，自引：0，他引：1
在野外地质观察、油气地球化学和样品分析的基础上,通过总结二次生烃特征和生烃机理,将其应用到中下扬子区海相高演化烃源岩生烃潜力的评价。模拟实验结果表明,二次生烃具有明显的迟缓现象,也仍具有相对的生烃高峰,二次生烃量与一次生烃量的总和小于连续热演化的生烃量,这些特征都与一次生烃的演化程度密切相关,初始演化程度成为评价高演化烃源岩二次生烃潜力的关键因素。中下扬子区中—古生界发育的6套烃源岩中,下二叠统、下志留统和下寒武统烃源岩具有较强的生烃能力,是主要的烃源层。下古生界烃源岩进入生烃时间较早,在强烈的构造运动背景下,生成的油气难以保存;上古生界烃源岩热演化程度相对较低,燕山—喜山期的再次沉降地区成为二次生烃的供源区。因此,下古生界台地相区和上古生界烃源岩具有一定的二次生烃潜力。 相似文献
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海参纲动物的吐脏再生 总被引：3，自引：0，他引：3
随着现代生命科学的迅猛发展,海参表现出的极强生命现象--再生,引起了生物学家的广泛兴趣、并被作为器官再生的模型来研究.当前,在我国迅速发展的刺参养殖业中,吐脏现象给养殖者造成了很大困惑.为了搞清刺参吐脏的原因、过程及影响因子,结合对中国北方养殖刺参的吐脏再生过程研究结果、参考国内外有关文献,综述了海参再生器官的细胞起源、迁移与增殖机理,以为刺参养殖提供理论参考. 相似文献
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Judith S. Weis 《Marine environmental research》1985,16(3):199-214
After multiple autotomy in the fiddler crab, Uca pugilator, cadmium retards limb regeneration and ecdysis. To study the effects of pre-exposure to lower levels of cadmium, groups were pre-exposed to 0·1, 0·5 or 1·0 mg liter?1 for a week prior to autotomy. Crabs were then placed in 1·0 mg liter?1 for regeneration. Pre-exposed groups were compared with groups of crabs which had not been pre-exposed to Cd. It was found that males pre-exposed to 0·5 mg liter?1 regenerated more rapidly in 1·0 mg liter?1 than those not pre-exposed. This phenomenon was not observed in females, in which none of the three pre-exposure concentrations were able to accelerate regeneration in 1·0 mg liter?1 relative to those not pre-exposed. In the pre-exposed males in which regeneration was accelerated and was comparable to control levels, no accompanying decrease of time until molting was observed. Therefore, the protective effect of pre-exposure would seem to be on the regeneration processes themselves and is not dependent on the neuroendocrine system which controls the molt cycle. 相似文献
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Abstract. The nutrient cycling of Epidavros, a deep basin in the Saronikos Gulf, was studied in relation to various environmental factors during 1973–1976 at a station characterized by stagnant conditions. The regeneration of nutrients was related to the consumption of oxygen, and a seasonal nutrient cycle occurred with low nutrient concentrations in the spring and summer, followed by high nutrient levels in autumn and winter. In addition high values of nitrate and silicate were observed in the deeper waters, which tended to be anoxic, although the water masses were renewed during spring 1974. The distribution pattern of nutrients together with nutrient ratios were compared with previous studies of the same and neighbouring areas as well as of other isolated basins. A stoichiometric model indicates that plankton organisms in the Epidavros basin have approximate atomic ratios for C: N: P of 150: 14:1, while the ratio of change for nitrogen and phosphorus in the water is only 8.8:1 by atoms. This is probably because of the slow rate of regeneration of nitrogenous material and/or assimilation and regeneration in organic forms. The water/plankton relation in the Epidavros basin appears to be very similar to that in the Baltic Sea. 相似文献
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H. C. Nilsson 《Journal of Sea Research》2000,44(3-4)
Interactions between ‘oxygen concentration’ (normoxia: >80% oxygen saturation, and hypoxia: 18% oxygen saturation) and ‘water flow velocity’ (low: 0.1 cm s−1, and moderate: 0.5 cm s−1) were studied on growth rates in the brittle star Amphiura filiformis in a flow-through aquaria system. Effects of ‘sublethal predation’ on growth rates were investigated as ‘number of amputated arms’ (1 and 3 arms) and ‘amputation of the disk’. A significant interaction between oxygen concentration and water flow velocity was observed in mean arm regeneration rate, but in both flow velocities higher mean arm regeneration rates were observed in normoxia compared to hypoxia. In hypoxia a positive response in arm regeneration rate was observed in moderate flow compared to low flow velocity. In normoxia, however, no response to flow velocity was observed. The latter observation indicates that Amphiura filiformis is able to maintain the ventilation of the burrow at low flow velocities, but in low oxygen concentrations hydrodynamic forces seem to affect growth. A significant interaction between oxygen concentration and disk amputation was observed in both arm and disk regeneration rates, indicating that the disk is the major organ for gas exchange in this species. The number of arms amputated, however, did not affect mean arm regeneration rate. The results obtained in this study suggest that the secondary production in subtidal infaunal populations could be negatively affected by low oxygen concentrations and that this response is even more negative in combination with low flow velocities in the near-bottom water. 相似文献