首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 59 毫秒
1.
克隆并测定了暗纹东方纯线粒体基因组(mtDNA)含完整的细胞色素氧化酶亚基Ⅲ(COⅢ)及其下游70bp的tRNA^cly序列。COⅢ基因编码框包含786个核苷酸,编码262个氨基酸的蛋白质。鱼类COⅢ的序列组成对A+T核苷酸的偏倚程度比较低。通过暗纹东方奎屯与GenBank中8个目12种鱼类的COⅢ序列同源性比较,显示暗纹东方纯与这些鱼类的COⅢ基因具有较高的同源性。根据暗纹东方纯与纯目其他5种鱼的COⅢ基因序列所建立的进化树。与传统的分类地位相吻合。推定的tRNA的二级结构具有典型的三叶草型结构。根据COⅢ序列构建的分子进化树分析,认为在采用线粒体基因序列进行分子进化分析时,应综合考虑物种遗传变异的特点。  相似文献   

2.
以暗纹东方纯(Takifugu fasciatus)肝脏的线粒体DNA为模板,按照红鳍东方豚(Takifugu rubripes)线粒体DNA序列设计合成特异引物进行PCR扩增,克隆并测定线粒体细胞色素b(Cyt b)及其侧翼tRNA基因的全序列,结果显示,克隆的暗纹东方纯Cyt b基因(1137bp)及其5’端上游的tRNA^Glu基因和3’端下游的tRNA^Thr基因序列共1327 bp。用DNA分析软件对暗纹东方纯与GenBank中10个目13种鱼类的Cyt b序列进行比较分析,显示暗纹东方纯与这些鱼类的Cyt b基因具有较高的同源性,与同属红鳍东方纯的同源性最高,为96.1%;与同目不同科的矛尾翻车纯(Masturus lanceolatus)和翻车纯(Mola mola)的同源性分别为74.1%和74.8%。tRNA^Glu基因由69个碱基组成,tRNA^Thr基因由72个碱基组成,与红鳍东方纯相应tRNA的碱基组成完全相同。推定的这两种tRNA的二级结构都具有典型的三叶草型结构,各臂的碱基配对率高,稳定性好。根据暗纹东方纯与其他13种鱼的Cyt b基因序列同源性所建立的进化树比较,结果与传统的分类地位基本吻合。  相似文献   

3.
暗纹东方鲀线粒体DNA控制区结构和系统发育分析   总被引:1,自引:0,他引:1       下载免费PDF全文
以暗纹东方(Takifugu fasciatus)肝脏线粒体DNA为模板,参照GenBank中红鳍东方(Takifugu rubripes)线粒体DNA序列设计合成特异引物进行PCR扩增,获得了暗纹东方线粒体DNA控制区基因(818 bp)及5′端上游的tR-NAPro基因(71 bp)的全序列。控制区碱基组成为T32.2%,C 19.1%,A35.6%,G13.2%。对照其他已报道的鱼类控制区结构,对暗纹东方控制区的结构进行了分析,识别了其终止序列区、中央保守区和保守序列区,找到了终止相关的序列TAS以及保守序列(CSB1,CSB2,CSB3)。CSB1、CSB2序列相对保守,TAS与其回文基序可形成稳定的茎环结构,成为H-链复制延伸时的终止识别位点。同时运用DNA分析软件对暗纹东方与GenBank中其他10多种鱼类的mtDNA控制区序列进行比对,并选取东方属的7种鱼类mtDNA控制区序列构建分子系统树。结果显示控制区基因较适于科鱼类中同属不同种的系统发育分析。  相似文献   

4.
暗纹东方鲀(Fugu obscurus(Abe))俗称河豚,由于其肉质细腻鲜美,被誉为长江“三鲜”之一,在我国华东地区有食用河豚的传统,市场前景看好。江苏中洋集团自1995年开始养殖暗纹东方鲍,已有十多年的历史,现已发展为全国最大的暗纹东方纯养殖基地,拥有国家级暗纹东方纯良种场,国家质量技术监督局授予南通地理标志性产品。经过多年的养殖,对于暗纹东方纯常见疾病及防治有独特的方法,现将在河豚养殖中的常见病害的流行与防治进行总结,供参考。  相似文献   

5.
陈勇  郭丽  陈舒泛 《水产科学》2008,27(5):251-253
利用聚合酶链式反应,首次从暗纹东方纯基因组DNA中扩增Hepcidin基因的部分序列,序列分析表明,不同鱼类之间的Hepcidin基因DNA序列之间的遗传距离为0.33~1.08,所获得的Hepcidin序列,为进一步研究暗纹东方纯中Hepcidin基因的作用机制提供了基础。  相似文献   

6.
养殖型暗纹东方鲀生长与发育特性   总被引:10,自引:1,他引:9  
华元渝 《水产学报》2004,28(1):8-14
观测养殖型暗纹东方鲀,获得4个年龄组的生长数据和解剖资料。拟合出雌、雄的体长体重关系和生长方程,分析其肥满度、胸腹围特点以及性腺和肝脏发育特点。结果显示,养殖型暗纹东方鲀雌雄体长生长规律相似;但体重在2.5龄前雄鱼生长速度大于雌鱼,2.5龄后则相反。养殖暗纹东方鲀体型比野生暗纹东方纯肥胖。体重/体长和肥满度皆大于野生型。研究还发现,养殖暗纹东方鲀性腺发育不良和肝脏脂肪变性发生率高,且两者的发生存在一定关系,致使全人工育成的成鱼繁殖难以成功。  相似文献   

7.
暗纹东方鲀仔鱼对药物的耐受性研究   总被引:1,自引:1,他引:0       下载免费PDF全文
采用急性攻毒的方法,进行硫酸铜、硫酸铜与硫酸亚铁合剂和福尔马林等三种水产养殖常用驱虫药物对暗纹东方纯仔鱼的毒性试验.结果表明:暗纹东方纯仔鱼对这三种药物敏感程度的大小顺序为:硫酸铜与硫酸亚铁合剂>硫酸铜>福尔马林;暗纹东方纯仔鱼对硫酸铜合剂的敏感性最强,安全浓度小于0.05 mg/L;硫酸铜的安全浓度为0.21 mg/L,24 h半致死浓度分别为1.03 mg/L和1.25 mg/L.暗纹东方鲀仔鱼对福尔马林的敏感性相对较弱,浸洗浓度至少可达20 mg/L.  相似文献   

8.
河豚的鱼肉鲜嫩味美,带有肉刺的鱼皮,胶质浓厚,食之黏口,味觉美感远胜于鱼翅、海参,因此被誉为“长江三鲜”之首。国内对河纯的育苗和养殖研究始于20世纪80年代初,首先由上海市水产研究所在东海渔政的支持下成立课题,在上海奉贤基地开展了暗纹东方纯的研究,其后,由黄海水产研究所在胶南基地陆续开展了红鳍、假睛、铅点、黄鳍等多种东方纯类的研究,80年代初,河北、山东、浙江、江苏、上海等地陆续开展了铅点东方鲍、红鳍东方纯、弓斑东方鲍、假睛东方纯、暗纹东方鲍、菊黄东方纯、豹纹东方纯的人工繁殖。  相似文献   

9.
暗纹东方纯(Takifugu obscurus)隶属鲀形目、鲍科、东方鲍属,俗名称河鲍、气泡鱼、河豚鱼。暗纹东方纯为海产的洄游性鱼类,春末夏初为生殖时期,成群溯河至长江中下游或鄱阳湖水系产卵。幼鱼在江河或通江的湖泊中肥育,至翌年春返至海中,  相似文献   

10.
河鲀异钩虫病是日本养殖红鳍东方鲀危害最大的寄生虫病,我国在2002年首次确认此病在养殖红鳍东方鲀时发生,笔者于2002年在暗纹东方鲀亲鱼越冬时发现,2003年和2004年一龄暗纹东方鲀越冬时又多次发现,是目前长江口区域养殖暗纹东方鲀鱼种时发病最严重的,损失最大的一种寄生虫病。本病全年均可发生,危害各生长阶段的河纯鱼,并且常常和纤毛虫病、车轮虫病、细菌病并发。  相似文献   

11.
Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km?2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks.  相似文献   

12.
Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs.  相似文献   

13.
Many lepisosteid populations in North America have declined and many are now threatened as a consequence of habitat loss and alteration and commercial and sport overfishing. Over the last two decades, morphological, histological and molecular studies allowed distinguishing between different phases of development and the nutritional condition of larvae. Ontogeny of the digestive enzymes of gar larvae indicated the possibility to feed them artificial feeds since early developmental stages. An in vitro digestibility system to test different feed ingredients has been used. Important characteristics of artificial diets were identified through different feeding experiments. Endocrinological studies showed the feasibility of altering larval development and the digestive capacity of larvae. Cloning of gar growth hormone opened new avenues to enhance growth in the gars. Plasmatic vitellogenin was isolated and purified, to develop a competitive enzyme‐linked immunosorbent assay, which allowed the straightforward separation of males from females to establish appropriate proportions for reproduction and also was used to evaluate hormonal protocols to induce gonad recrudescence and spawning. This review analyzes the biology, ecology and physiology of different gar species as a basis for their domestication, mass production of larvae for repopulation experiments and for the culture of commercial‐size gar.  相似文献   

14.
奶牛酮病发病机理研究进展   总被引:2,自引:0,他引:2  
结合国内外目前研究状况较为详细的综述了奶牛酮病的病因与发病机理,并分析了奶牛酮病发生的生化机制。旨在对临床实践中很好的认识诊断和群体监控奶牛酮病提供较为系统的理论依据,保证奶牛群的高产和稳产,从而创造良好的经济效益。  相似文献   

15.
李佳  吴东波 《畜禽业》2007,(4):8-11
本试验利用饲养试验方法,研究玉米-豆粕型日粮中添加植酸酶时不同磷水平和钙磷比对生长肥育猪血清指标和骨骼性能的影响。试验选用162头20kg左右的杜长大三元杂交猪进行2×3(磷水平×钙磷比)因子饲养试验,试验分2个阶段进行,前期为生长期体重在20-60kg,后期为肥育期体重为为60-100kg。结果表明:添加植酸酶日粮磷水平对血清磷含量和碱性磷酸酶的活性影响显著(P<0.05);钙磷比对血清钙和血清磷含量的影响显著(P<0.05);添加植酸酶日粮磷水平和钙磷比对生长肥育猪骨骼性能的影响不显著(P>0.05)。在添加植酸酶条件下,降低日粮磷水平不影响猪的正常生长发育。  相似文献   

16.
A report is presented of esophagoscopy and gastroscopy in cats and dogs using flexible endoscopes. Following consideration of the basic equipment, an account is given of patient preparation and anesthesia, topography, investigation technique and normal findings. Diagnostic potential, indications and risks involved are discussed.  相似文献   

17.
“十一五”以来,我国农垦加快体制机制改革、结构调整和经济增长方式的转变的步伐,参与市场竞争,努力提升企业和产品竞争力,经济社会事业发展较快,对国家的贡献提升,职工收入、生活质量明显提高和改善,示范引领作用不断增强。本文针对农垦体制机制创新进展滞缓,战略定位与发展方向不明,经济增长方式转变和结构调整缺乏资本、人才、技术的支撑,没有处理好改革、发展、稳定、民生的关系,投资匮乏,发展后劲不足,人才短缺和劳动力素质低下的现状,提出在未来农垦体制机制创新中要特别关注改革方向、目标设定与评估,改革要在现行法律法规的框架内运作,改革时机的选择,处理好改革发展稳定与民生的关系,调整好内部利益分配关系,自觉融入区域经济,与地方协同发展等问题。为了促进农垦的发展,建议国家加大对农垦体制机制创新、现代农业建设、国有农场土地资源的保护、社会保障体系的完善等财政和政策的支持力度。  相似文献   

18.
温度与盐度对老年低额蚤和蚤状蚤生长及生殖的影响王丹丽,李明云,杨天勇,胡章(宁波大学,315010)关键词老年低额 ,蚤状 ,温度,盐度,生长,生殖EFFECTSOFTEMPERATUREANDSALINITYONGROWTHANDREPRODUCT...  相似文献   

19.
鸡皮刺螨是鸡的一种体外寄生的节肢动物,流行十分广泛,对养殖业发展有严重影响。为了解鸡皮刺螨的发病情况,对川渝两地的126个鸡场进行流行病学调查,感染率高达71%。同时,介绍了鸡皮刺螨的生活史、危害及防治措施,是防制鸡皮刺螨不可多得的资料。  相似文献   

20.
Abstract  Catch composition, relative abundance and diversity of fish catches in open access and three old fisheries closures were compared and contrasted with previous ecological studies. There was less variation in catch community composition among the fishing grounds than the closures, suggesting that fishing has homogenised catch composition. The trap survey found that some parrotfish [ Leptoscarus vaigiensis (Quoy &Gaimard), Calotomus carolinus (Valenciennes) and Scarus ghobban Forsskål] were relatively more common and that some important predators of macro-invertebrates [ Balistapus undulatus (Mungo Park) and Cheilinus chlorourus (Bloch)] were less common in the fishing grounds than closures. Unexpectedly, and in contrast to visual census results, cumulative number of species in catch surveys was higher in open access than closures sites. This may result from fishers covering more area and habitat or a reduction in the catch of competitively subordinate and rare species by aggressive, early-caught fish that can dominate bait. Comparisons of ecological visual census surveys and fisheries-dependent methods indicated that small differences in catch composition can reflect larger ecological differences and that baiting methods can underestimate biodiversity. Ecological impacts of fishing and large-scale changes in marine ecosystems must be considerable given the many fisheries-dependent assessments report modest changes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号