共查询到20条相似文献，搜索用时 62 毫秒
1.
运用微卫星分子标记对80尾胭脂鱼人工放流子一代个体的遗传多样性和种群遗传结构进行了分析。用磁珠富集法构建了胭脂鱼(AAAG)n富集文库,从中分离并鉴定得到的22个微卫星位点最终设计合成18对引物。对长江中、上游的80尾人工增殖放流的胭脂鱼子一代进行了遗传多样性的初步研究,其中5对引物呈现多态性,等位基因数目为 2～8个;多态信息含量0.2957～0.8038;Shannon多样性指数0.5466～1.8840;观测杂合度0.3056～0.7222;期望杂合度0.3658～0.8381;Hard-Weinberg遗传偏离指数（D）-0.1818～0.4287。结果初步表明,胭脂鱼人工放流子一代处于较高的遗传多样性水平,但很大程度上仍受到人类活动的影响。 相似文献
2.
日本蟳微卫星富集文库的建立与多态性标记的筛选 总被引：2，自引：1，他引：1
采用磁珠富集法筛选日本蟳微卫星分子标记。日本蟳基因组DNA经Sau3 AⅠ酶切后,收集400~1 200 bp大小的片段并纯化,利用生物素标记的寡核苷酸探针(AC)15从中筛选出含有微卫星序列的DNA片段,连接到pMD18-T载体中,构建富集微卫星序列的基因组文库,经PCR检测筛选出阳性克隆进行测序。从随机挑选的970个菌落中筛选出369个阳性克隆进行测序,结果86.99%(321个)含有微卫星序列,其中完美型占80.54%,非完美型占15.95%,混合型占4.28%。除使用的探针AC重复外,还得到GA、CT等重复序列。共设计出102对微卫星引物,其中65对能扩增出清晰条带,27对具有多态性。同时筛选出的微卫星标记可为今后研究日本蟳的分子遗传育种提供有效的遗传标记。 相似文献
3.
以剑尾鱼(Xiphophorus helleri)为材料,经MboⅠ限制性内切酶消化基因组DNA后,选取500～2 000 bp的片段连接到经BamHⅠ酶切的pUC18载体上,转化大肠杆菌DH5α构建部分基因组文库.采用设计合成的(AC)7、(GT)7重复序列为引物,PCR筛选部分基因组文库,对其中9个重组阳性克隆进行测序,结果共获得24个微卫星序列,其中Perfect(完美型)13个,占54.2%;Imperfect(非完美型)3个,占12.5%;Compound(混合型)8个,占33.3%.表明(AC/GT)n在剑尾鱼的基因组DNA中含量非常丰富.同时,根据其中3个克隆微卫星的侧翼序列设计引物,PCR扩增剑尾鱼基因组DNA,结果均扩增到目的片段.而且,这3对引物扩增出来的微卫星片段在非选育的剑尾鱼中显示出多态性,而在近交系19代则表现为单态,为剑尾鱼的实验动物化遗传研究提供了理论依据. 相似文献
4.
牙鲆基因组 (CAG)n微卫星 DNA 特征分析 总被引：1，自引：0，他引：1
通过磁珠富集法筛选牙鲆(Paralichthys olivaceus)的微卫星分子标记,采用限制性内切酶Sau 3A Ⅰ对牙鲆完整基因组DNA进行酶切;通过蔗糖溶液梯度离心,收集400～900 bp大小的片段,连接Brown接头,构建牙鲆基因组文库.用生物素标记的微卫星探针(CAG)15,对基因组文库进行杂交,利用磁珠富集含有微卫星的DNA单链序列,并对其进行PCR扩增;将扩增产物连接到pMD18-T载体后转入感受态大肠杆菌DH5α中,得到微卫星序列文库.利用大量质粒检测法进行二次筛选,成功地从牙鲆基因组中分离出含有CAG重复的微卫星序列,测序其中的3000个单菌落,获得2805个(占93.5%)含有微卫星序列的克隆,其中含有微卫星座位3120个,完美型1808个,占57.97%;非完美型226个,占7.25%;混合型1085个,占34.78%.从中选出186个微卫星序列设计120对引物并合成,经过筛选,74对引物可扩增清晰条带,其中68对呈多态性. 相似文献
5.
青蟹微卫星DNA的筛选及特征分析 总被引：1，自引：0，他引：1
利用磁珠富集法,结合生物素标记的(CA)16寡核苷酸探针从青蟹基因组MboI酶切片段中筛选微卫星DNA序列.将得到的片段与pGEM-T Easy载体连接后转化克隆构建微卫星富集文库.经PCR筛选检测,对89个阳性克隆进行测序,其中52个克隆中含有64个微卫星,完全型占87.50%,重复次数超过11次的占78.12%.根据所获微卫星的侧翼序列设计并合成了30对引物,通过优化PCR反应条件,并在35只青蟹个体中进行PCR扩增检测,最终获得了10对具有多态性的引物,为进一步开展青蟹遗传多样性分析、遗传图谱构建等研究提供了基础资料. 相似文献
6.
采用人工合成的生物素标记(AG)15探针及磁珠富集法构建了脊尾白虾基因组微卫星富集文库.将脊尾白虾基因组DNA经HaeⅢ酶切后,收集400 ～1 200 bp片段,连接特定接头,与生物素标记(AG)15探针杂交并捕获含有微卫星的DNA片段,然后连接到pMD18-T载体中,构建脊尾白虾微卫星富集文库.随机挑取947个克隆,经菌落PCR检验,其中667个为阳性克隆.从阳性克隆中随机选取184个克隆进行测序,有150个克隆含有微卫星序列,共获得199个微卫星序列,其中完美型158个(79.4％),非完美型27个(13.6％),复合型14个(7.0％).根据微卫星序列,设计了119对微卫星引物,64对扩增出稳定的具有特异性的条带,经30个脊尾白虾个体进行多样性评价后,有26个位点表现出多态性.26个微卫星位点获得的等位基因数从3 ～ 16个不等,平均每个位点扩增得到6.5个等位基因.观测杂合度(Ho)、期望杂合度(4)及多态性信息含量值(PIC)的范围分别为0.111 ～ 0.929、0.246 ～0.932、0.231 ～0.909.本研究开发的微卫星位点将为脊尾白虾种群多样性研究、家系识别和种质鉴定提供有效的工具. 相似文献
7.
运用生物素与链霉亲和素的强亲和性原理,用生物素-磁珠吸附微卫星富集法,筛选企鹅珍珠贝(Pteria penguin)的微卫星分子标记序列,进而对南海区企鹅珍珠贝的遗传多样性进行分析。对136个菌落中的85个阳性克隆进行微卫星测序,获得64个序列,达到85.93%。所得到的55个重复6次以上的微卫星序列中,除生物素探针中使用的CA重复外,还得到TG、TC、GA的重复序列。重复序列中完美型36个,占65.5%;不完美型14个,占25.5%;混合型5个,占9.1%。利用Primer Premier5.0设计引物40对,合成其中的20对并进行PCR筛选,15对可扩增出特异性条带。研究表明,筛选出的企鹅珍珠贝微卫星分子标记可用于进一步的遗传多样性分析。 相似文献
8.
青石斑鱼微卫星DNA 标记的筛选及群体遗传多样性分析 总被引：5，自引：0，他引：5
以中国南海海域青石斑鱼（Epinephelus awoara）为材料，构建青石斑鱼小片段部分基因组DNA文库。以M13通用引物和设计合成的微卫星核心序列引物（CA）15,用PCR法对文库进行筛选，共获得96个微卫星序列，分别分布于28个阳性重组克隆中，其中perfect（完美型）共39个（占40．6％），imperfect（非完美型）30个（占31．3％），compound perfect（混合完美型）7个（占7．3％），compound imperfect（混合非完美型）20个（占20．8％）。同时发现（CA／GT）。序列在青石斑鱼的基因组DNA中含量非常丰富。根据微卫星侧翼序列设计28对引物扩增青石斑鱼基因组DNA，有26对引物能扩增出目的片段，选用其中13对多态性稳定的引物对19尾青石斑鱼进行遗传多样性分析。结果显示，13个位点共检测到48个等位基因，平均观测杂合度（Ho）为0．5982，平均期望杂合度（He）为0．5080，平均多态信息含量（PIC）为0．4722，平均Hardy-Weinberg遗传偏离指数（D）为0．1503。实验初步表明中国南海海域青石斑鱼的遗传多样性较为丰富，但在某种程度上受到了人为的干扰。 相似文献
9.
将牙鲆基因组DNA经限制性内切酶RsaⅠ和BstUI双酶切后采用FIASCO法构建酶切片段基因组文库。共挑取269个克隆,177个为阳性克隆,阳性克隆率为65.79%。经测序后获得191条微卫星序列,其中完美型占74.35%;非完美型占14.66%;混合型占10.99%。用引物设计软件Primer Premier 5.0设计引物153对,挑选其中的50对合成并在32个野生牙鲆个体中进行扩增,共31个位点具有多态性,统计结果后使用POPGENE软件进行分析,平均等位基因个数为3.939 4,平均有效等位基因数为3.052 2,平均观测杂合度为0.650 1,平均期望杂合度为0.586 6,各引物的Hardy-Weinberg平衡指数在0.012 587~0.984 917变动。这些筛选出的多态性微卫星标记可应用于进一步的牙鲆遗传多样性分析、家系分析及遗传图谱的构建等工作中。 相似文献
10.
日本沼虾微卫星引物筛选及群体遗传多样性分析 总被引：5，自引：2，他引：3
采用(CT)15、(CA)15两种生物素标记及磁珠富集法构建了太湖日本沼虾基因组微卫星富集文库。120个微卫星克隆中83个位点的核心序列重复在10个以上,长度介于191～580bp,平均为311bp;重复类型中,(CA/GT)n及(AG/TC)n分别占59.09%及20.45%,还检测到(GC)n、(AAG)n、(ACAA)n和(GGCAGA)n等17种类型,包括25.75%完美型、20.45%非完美型和53.80%复合性。用其中12条微卫星引物扩增吴江、滨湖、宜兴和吴兴4个群体240个个体的基因组DNA,各位点表现出较高的遗传多样性,除Mni86、Mni103和Mni114外,其它群体位点大都表现出显著的杂合子缺失,4个群体的遗传分化为低度分化(FST<0.05),4个群体中97.58%遗传变异存在于群体内,仅有2.42%的遗传变异来自于群体之间;吴江和吴兴群体亲缘关系最近,与宜兴和滨湖群体亲缘关系渐远。 相似文献
11.
Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
下载免费PDF全文
下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
12.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
13.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
14.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
15.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
16.
Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献
17.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献
18.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
19.
T. Citarasu K. Venkatramalingam M. Micheal Babu R. Raja Jeya Sekar M. Petermarian 《Aquaculture International》2003,11(6):581-595
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could
lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment
in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load
in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
20.
William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献