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版纳鱼螈Ichthyophis bannanicus是蚓螈目Gymnophiona在我国分布的唯一物种.由于长期以来缺乏对版纳鱼螈的分布范围及演化历史等信息的了解,本研究通过分子遗传学的方法,就其分布、起源及扩散等内容进行了探讨.结果发现,我国境内的版纳鱼螈均属同一物种,尚未出现种的分化.研究中明确证实了版纳鱼螈在泰国和越南的分布,提示了版纳鱼螈在中南半岛广为分布,甚至可能达到马来西亚境内.结果还提示水系对版纳鱼螈的分布具有较大的影响,尤其在湄公河水系中表现的最为明显.现有的信息提示版纳鱼螈有可能起源于中南半岛,并沿着澜沧江-湄公河水系、红河-珠江水系、克拉地峡-马来半岛3个方向扩散.我国境内的版纳鱼螈主要分布在云南南部地区和两广丘陵以南,来自这两大分布区的个体之间的遗传差异明显,应属于不同的进化显著单元. 相似文献
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版纳鱼螈Ichthyophis bannanicus 是蚓螈类在我国分布的唯一物种,目前已知分布在云南、广西和广东的部分地区.本研究获得4个版纳鱼螈种群的87个个体的线粒体DNA细胞色素6基因1 000 bp序列,对序列变异、遗传多样性、种群结构和种群动态进行了分析.经比对后87个序列发现39个(3.9%)多态性位点,共定义了22个单倍型.序列分析结果显示版纳鱼螈种群单倍型多样性和核苷酸多样性与其它两栖动物接近,说明版纳鱼螈各种群仍保持一定的遗传多样性水平.单倍型网络关系图和系统发生分析均显示来自云南和两广地区的版纳鱼螈分歧明显,已形成了不同的进化谱系.种群遗传结构分析也显示来自云南的勐腊种群与两广各种群之间显著的遗传差异,这提示分布在云南与两广地区的版纳鱼螈应作为不同的管理单元(MU)进行保护.综合两种中性检验(Fu's Fs=9.44,P=0;Tajima's D=1.88,P=0.013)和种群增长指数(g=5415.03±297.55)分析的结果表明,两广地区的版纳鱼螈可能经历近期的种群扩张事件. 相似文献
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版纳鱼螈和双带鱼螈核型的比较研究 总被引:9,自引:0,他引:9
本文对版纳鱼螈的核型作了观察,并与双带鱼螈进行了比较。两者的核型基本一致,均为2n=42,但版纳鱼螈的NF=62,而双带鱼螈的NF=60;版纳鱼螈的染色体有中部着丝粒、亚中部着丝粒和端部着丝粒三种类型,而双带鱼螈则无亚中部着丝粒的染色体。 相似文献
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版纳鱼螈外周血细胞观察 总被引:5,自引:2,他引:3
以濒危两栖动物版纳鱼螈(Ichthyophis bannanica)为材料,应用瑞氏-姬姆萨混合染色法与血细胞计数法观察并统计了版纳鱼螈各种外周血细胞的形态特征和数量比例.结果表明,版纳鱼螈的外周血液中红细胞数量较多,呈卵圆形、椭圆形、梭形和梨形,平均含量为2.57 ×105个/mm3.白细胞数量较少,多呈近圆形,平均含量为0.72×103个/mm3.白细胞中,淋巴细胞最多,其次为单核细胞、嗜中性粒细胞、嗜碱性粒细胞和嗜酸性粒细胞.血栓细胞数量较少,常数个集合在一起.同时,将此研究结果与鱼类、爬行类和其他两栖类的血细胞比较,进而探讨了版纳鱼螈的进化地位. 相似文献
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《四川动物》编辑部:感谢您在过去一年里的对我的关心和支持!2006年5月我在贵刊2006年25卷2期发表《版纳鱼螈研究进展》,同年在《动物学杂志》41卷4期发表《版纳鱼螈的骨骼系统》。自这两文发表以来,我收到了数位关心该研究方向的读者来信,共同反映一个问题:《版纳鱼螈研究进展》一文“2.7骨骼研究”一段中提到“国内尚无学者关注版纳鱼螈的骨骼研究,国外仅有MtthewW.Colbert和David Canatella 2004年采用CT扫描的方法展示了版纳鱼螈头骨的三维结构,并制作成了动画电影“,而在《版纳鱼螈的骨骼系统》之前言部分又说:”到目前为止国内外尚… 相似文献
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版纳鱼螈侧线系统的结构 总被引:5,自引:0,他引:5
版纳鱼螈(Ichthyophis bannanica)是我国无足目的仅有代表,应用光镜和扫描电镜对版纳鱼螈的侧线系统进行形态学和组织学观察的研究表明:版纳鱼螈幼体表皮中的侧线器官有接受机械刺激的神经丘和电接受壶腹器官两种,神经丘包括表面神经丘和陷神经丘。侧线分布主要包括:头部的鼻侧线、眶上线、眶下线、眶后线、口侧线、下颌线、咽侧线、鳃孔上线和身体上的背侧线。侧线器官的分布密度、大小和凹陷深度明显与周围表皮的厚度和不同部位有关。幼体的侧线器官退化与鳃孔的退化同步,亚成体以后不保留侧线系统。版纳鱼螈的侧线分布和器官结构与其它无足类的大致相似,仅在眶上线和眶下线的器官分布上存在微小的差别 相似文献
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版纳鱼螈脑的解剖学与组织学 总被引:1,自引:0,他引:1
应用光镜对蚓螈目(Gymnophiona)物种版纳鱼螈(Ichthyophis bannanicus)脑的解剖和组织结构进行观察。结果表明,版纳鱼螈脑可分为端脑、间脑、中脑和延脑4个部分,端脑由嗅球、副嗅球和大脑半球构成。嗅球发达,有两对嗅神经;大脑半球呈长椭圆形,为脑的主要部分;间脑腹面向后以漏斗连有扁平勺状的垂体;中脑椭圆形;没有小脑;延髓有较大弯曲。本文同时就上述结构特征与其他两栖动物相比较,探讨了在神经系统演化中版纳鱼螈脑的结构的原始性。 相似文献
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Williams N 《Current biology : CB》2003,13(12):R461-R462
The decline and loss of species is inevitable in the face of growing human pressures on the environment but, according to one group of senior researchers, a standard framework is needed to assess the rate of this decline if researchers wish to be effective and policymakers are to take note. 相似文献
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Samuel D. McQuillin Michael D. Lyons Rebecca J. Clayton Jacqueline R. Anderson 《应用发育科学》2020,24(3):215-229
ABSTRACTLike many youth development programs, most youth mentoring programs do not have prescribed practices that target specific outcomes. Because the construct of mentoring represents a broad range of potential activities, researchers face a conundrum when making generalizable causal inferences about the effects of this and similar services. On the one hand, researchers cannot make valid experimental inferences if they do not describe what they manipulate. On the other hand, experiments that include prescribed protocols do not generalize to most mentoring programs. In most cases, researchers conducting school-based mentoring program evaluations err on the side of not sufficiently specifying treatment constructs, which limits the field’s ability to make practically or theoretically useful inferences about this service. We discuss this reality in light of the fundamental logic of the experimental design and suggest several possible solutions to this conundrum. Our goal is to empower researchers to adequately specify treatments while still preserving the treatment construct validity of this and similar interventions. 相似文献
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Ebner BC Kroll B Godfrey P Thuesen PA Vallance T Pusey B Allen GR Rayner TS Perna CN 《Journal of fish biology》2011,79(1):70-79
Analysis of 36 records of the rarely encountered moray Gymnothorax polyuranodon indicate that juveniles and adults inhabit fresh and mildly brackish habitats (salinity < 5) in streams of the Australian Wet Tropics Eighty-one per cent of these records were from freshwater streams and collectively demonstrate that this species inhabits fresh water throughout all seasons. A survey of fish researchers, each with at least 100 h of field experience in Australia's Wet Tropics, revealed that 33% of researchers working in fresh waters (nine of 27 researchers) had encountered the species and 15% of researchers with substantial experience working in estuaries (two of 13 researchers) had encountered the species. The species was not sampled or observed in the nearshore marine environment. The only record of an elver of this species was, however, found in an estuary at a salinity of 33·4. This preliminary evidence suggests adult G. polyuranodon occupy freshwater habitats, but further research is required to understand the complete life cycle, including movements, habitat use and reproductive ecology of the species. 相似文献
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TRISHA PHILLIPS 《Bioethics》2011,25(4):209-219
Offering cash payments to research subjects is a common recruiting method but there is significant debate about whether and in what amount such payments are appropriate. This paper is concerned with exploitation and whether there should be a lower limit on the amount researchers can pay their subjects. When subjects participate in research as a way to make money, fairness requires that researchers pay them a fair wage. This call for the establishment of a lower limit meets resistance in two places: (1) denial that the payments offered by researchers are wages for participation; and (2) concern about undue inducement. This paper critically examines these arguments for and against a lower limit. It shows that the need for a lower limit cannot be avoided by adopting a non‐wage payment model and that concerns about undue inducement are unjustified in all trials except those that present greater than minimal risk. This analysis suggests the following compromise position: there should be an unconditional lower limit on payment amounts so that researchers cannot offer less than a fair wage, and when researchers cannot satisfy this limit because fairness requires a problematically large payment, then researchers should offer no payment at all. 相似文献
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Material transfer agreements exist to facilitate the exchange of materials and associated data between researchers as well as to protect the interests of the researchers and their institutions. But this dual mandate can be a source of frustration for researchers, creating administrative burdens and slowing down collaborations. We argue here that in most cases in pre-competitive research, a simple agreement would suffice; the more complex agreements and mechanisms for their negotiation should be reserved for cases where the risks posed to the institution and the potential commercial value of the research reagents is high. 相似文献
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Iain S. Haslam Ralf Paus 《BioEssays : news and reviews in molecular, cellular and developmental biology》2020,42(11):2000053
Skin is a comparatively accessible organ possessing many conserved regulatory and signaling pathways, drawing researchers from varied fields toward its study. Hair follicle (HF) biology in particular has expanded rapidly over the preceding decade, helping to shape and develop scientific knowledge across diverse areas of biomedical research, beyond the skin. The hope in compiling this review is to inspire more researchers to utilize the HF as an instructive biological model, bringing with them fresh perspectives and experience from differing fields of study. The authors also wish to further motivate seasoned hair researchers to explore the further reaches of their understanding and the discoveries yet to be made. For this reason, the authors have endeavored to collate an eclectic mix of some of the most thought-provoking and scientifically intriguing articles associated with the field of HF research, published in the preceding two years. 相似文献
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方瑶毛旭虎 《现代生物医学进展》2012,12(22):4358-4359
RAW264.7细胞具有很强的黏附和吞噬抗原的能力,是研究微生物学、免疫学的常用细胞株.很多研究者发现这种细胞形态极不稳定,细胞状态的评价也很困难.本文作者结合RAW264.7培养经历及文献资料探讨RAW264.7细胞培养的经验教训和评价细胞状态的方法,旨在为培养该细胞的科研工作者提供一定的借鉴. 相似文献
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Jerod A. Merkle Neil J. Anderson Danna L. Baxley Matthew Chopp Laura C. Gigliotti Justin A. Gude Tyler M. Harms Heather E. Johnson Evelyn H. Merrill Michael S. Mitchell Tony W. Mong Jerry Nelson Andrew S. Norton Michael J. Sheriff Eric Tomasik Kelly R. VanBeek 《The Journal of wildlife management》2019,83(8):1644-1651
Although most wildlife professionals agree that science should inform wildlife management decisions, disconnect still exists between researchers and managers. If researchers are not striving to incorporate their findings into management decisions, support for research programs by managers can wane. If managers are not using research findings to inform management decisions, those decisions may be less effective or more vulnerable to legal challenges. Both of these situations can have negative consequences for wildlife conservation. We outline a collaborative research-management approach to bridging the gap between wildlife managers and researchers. We describe differences in perspectives, perceptions, and priorities between managers and researchers; outline how and why the divide between researchers and managers has likely occurred and continues to grow; and present specific strategies and recommendations to foster stronger collaborations between managers and researchers. We advocate increased synergy between managers and researchers based on a shared vision of conservation and a collaborative structure that rewards researchers and managers. Most importantly, we suggest that relationships and communication between managers and researchers must be established early in research development and decision-making processes, fostering the trust needed for collaboration. Institutions and agencies can facilitate these relationships by creating opportunities and incentives for integrating collaborative research into management decisions. We suggest this approach will strengthen ties between researchers and managers, increase relevance of research to management decisions, promote effectiveness of management decisions, reduce legal challenges, and ultimately produce positive, tangible, and lasting effects on wildlife conservation. © 2019 The Wildlife Society. 相似文献