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1.
采用PCR-RFLP分析方法,对洞庭湖、武汉两地的二倍体和四倍体泥鳅线粒体DNAND-5/6基因多态性及4个群体遗传变异和遗传关系进行了研究。结果表明,120尾泥鳅mtDNAND-5/6扩增片段长度均为2.2kb;从13种限制性内切核酸酶中筛选出6种多态性内切酶(HaeⅢ、DraⅠ、RsaⅠ、TaqⅠ、HinfⅠ、MspⅠ),对扩增产物进行酶切,共检测到66种单倍型。泥鳅群体内单倍型多样性和核苷酸多样性分别为0.7679～0.9385和0.01041～0.03212;其中,洞庭湖二倍体核苷酸多样性最高(0.03212),武汉二倍体其次(0.02452),二倍体群体内核苷酸多样性高于四倍体。群体间的核苷酸多样性(π)大小为0.02588～0.04144,平均值为(0.031737±0.000005)。群体间的核苷酸歧化距离(δ)大小为0.00462～0.01617,平均值为(0.010659±0.000003);其中,武汉二倍体和四倍体之间的核苷酸歧化距离最大(0.01617),武汉四倍体和洞庭湖二倍体之间的核苷酸歧化距离最小(0.00462)。MonteCarlo模拟x2检验表明,4个群体间的单倍型频率存在极...  相似文献   

2.
为评估泥鳅、大鳞副泥鳅选育群体的遗传育种潜力,通过聚合酶链反应(PCR)扩增和一代测序技术,获得经两代群体选育的泥鳅自繁(M)、大鳞副泥鳅自繁(P)及其正交(MP)、反交(PM)等4个子代泥鳅种群的线粒体细胞色素氧化酶亚基Ⅰ基因COⅠ片段,并分析了其遗传多样性和群体结构。结果显示：(1)4种泥鳅的COⅠ基因片段碱基组成相似,均表现为A+T的含量(54.0%～56.2%)高于C+G的含量(43.8%～46.4%);(2)4种泥鳅COⅠ基因片段的682个位点中,共检测到135个多态位点(占19.79%),其中128个为简约信息位点,7个为单碱基变异位点,变异均为转换或颠换,未发现碱基的插入与缺失;(3)M、P、MP、PM各定义15个单倍型,单倍型多态性均为1.000±0.024,核苷酸多态性分别为0.020 66±0.006 48、0.025 80±0.002 31、0.029 61±0.005 62和0.022 30±0.001 94,均具有高单倍型多样性和高核苷酸多态性;(4)M、P、MP、PM种内遗传距离分别为0～0.020、0～0.024、0～0.027和0～0.023,种间遗传距...  相似文献   

3.
采用PCR-RFLP方法,对采自安徽怀远、河南范县及安徽舒城的3个群体共112尾泥鳅(Misgurnus anguilli-caudatus)线粒体DNA(mtDNA)的D-loop区段进行PCR扩增,使用11种核酸限制性内切酶进行酶切。结果显示,在11种内切酶中,8种有酶切位点,4种存在个体间变异,共产生7种单倍型。怀远、范县和舒城群体的核苷酸多样性指数为0.0033、0.0083、0.0011,单倍型多样性指数分别为0.6048、0.8370、0.2344。范县与怀远、舒城群体间的Rogers遗传距离分别为0.3456和0.6847,怀远和舒城群体间的Rogers遗传距离为0.6326。SspⅠ的酶切类型C组成的单倍型在舒城群体中占87.5%,而在范县群体中为0;同时发现,SspⅠ的酶切类型C、D和XspⅠ的酶切类型B分别组成的单倍型仅在范县群体中存在。  相似文献   

4.
采用PCR-RFLP方法,对采自安徽怀远、河南范县及安徽舒城的3个群体共112尾泥鳅（Misgurnus anguilli-caudatus）线粒体DNA（mtDNA）的D-loop区段进行PCR扩增,使用11种核酸限制性内切酶进行酶切。结果显示,在11种内切酶中,8种有酶切位点,4种存在个体间变异,共产生7种单倍型。怀远、范县和舒城群体的核苷酸多样性指数为0.0033、0.0083、0.0011,单倍型多样性指数分别为0.6048、0.8370、0.2344。范县与怀远、舒城群体间的Rogers遗传距离分别为0.3456和0.6847,怀远和舒城群体间的Rogers遗传距离为0.6326。SspⅠ的酶切类型C组成的单倍型在舒城群体中占87.5%,而在范县群体中为0;同时发现,SspⅠ的酶切类型C、D和XspⅠ的酶切类型B分别组成的单倍型仅在范县群体中存在。  相似文献   

5.
为了解江苏省主要湖泊内太湖新银鱼(Neosalanx taihuensis)的遗传背景,利用PCR扩增江苏省太湖、高邮湖、洪泽湖和骆马湖4个群体153尾样本的COⅠ基因序列,并进行测序和分析。经比对获得630 bp的基因序列片段,检出7个变异位点,其中简约位点3个,单一位点4个。153尾个体共定义9个单倍型,单倍型多样性为0.580±0.022(0.050±0.047～0.361±0.103),核苷酸多样性为0.001 06±0.000 07(0.000 08±0.000 07～0.000 62±0.000 20),呈现出较低的单倍型多样性和核苷酸多样性的特点。4个群体间的遗传距离为0.000 12～0.001 83。AMOVA分子方差分析表明,太湖新银鱼群体间的遗传差异(76.84%)大于群体内遗传差异(23.16%),遗传变异主要来自群体间。种群间遗传分化系数统计检验表明,太湖和洪泽湖群体及高邮湖和骆马湖群体之间差异不显著。中性检验和歧点分布分析表明,4个太湖新银鱼种群偏离中性进化,历史上经历过种群扩张。研究可为太湖新银鱼种质资源科学保护和合理利用提供理论依据。  相似文献   

6.
3个群体草鱼mtDNA D-Loop的PCR-RFLP分析   总被引：10，自引：0，他引：10  
采用PCR技术对江西瑞昌、湖南长沙、天津宁河3个群体的144尾草鱼线粒体DNA（mtDNA）D—Loop区段的限制性片段长度多态性（RFLP）进行了分析。PCR扩增出的mtDNA D—Loop区段，用11种核酸内切限制酶酶切。结果显示：扩增出的142尾试验鱼的mtDNA D-Loop区段为1．6kbp，长沙群体中的两尾为1．8khp，个体间存在长度变异现象；6种限制酶具有酶切位点，共检测到两种单倍型，其中长沙群体中有长度变异的两尾为一种单倍型，142尾为另一种单倍型；瑞昌和宁河两群体内的单倍型多样性指数、核苷酸多样性指数均为0，长沙群体内的分别为0．0816、0．00315；长沙群体与瑞昌（或宁河）群体间的核苷酸歧化距离以及Rogers遗传距离分别为0．0000343和0．6783；X^2检验结果显示3个群体间的遗传差异不显著（P〉0．05）。表明离草鱼mtDNA D—Loop区段的遗传多样性很低。  相似文献   

7.
为了解大鳞副泥鳅群体遗传多样性现状,实验利用线粒体COI基因部分序列对来自于辽宁、河南、湖北和台湾的大鳞副泥鳅4个群体进行了遗传多样性分析。结果显示,在642 bp的COI基因序列中,碱基A、T、C、G的平均含量分别为23.5%、30.6%、26.7%、19.2%,表现出较强的AT偏好性;4个群体共检测到44个多态性位点,定义了23个单倍型;4个群体的单倍型多样性指数(h)为0.424～0.855,核苷酸多样性指数(π)为0.000 84～0.016 59,台湾群体遗传多样性较高,河南群体次之,湖北群体和辽宁群体较低;群体间遗传分化系数FST及遗传距离分析表明,台湾群体与其他群体间均存在极显著的遗传分化,且与其他群体间的遗传距离均较远;AMOVA分析结果表明,群体间的遗传变异高于群体内的变异(52.11%47.89%);辽宁、河南和湖北群体的中性检验Tajima’s D及Fu’s Fs均为负值,提示辽宁、河南和湖北群体可能经历过群体爆发和扩张事件。研究表明,大鳞副泥鳅不同地理群体形成了一定的遗传分化,研究结果为大鳞副泥鳅的遗传多样性保护及选育等工作提供了依据。  相似文献   

8.
采用PCR技术对乌克兰鳞鲤、德国镜鲤、框鳞镜鲤、红镜鲤和州河鲤共97尾个体的线粒体DNA D-loop及邻近区段进行了扩增,经测序后获得碱基顺序排列清晰的DNA片段,长度分别为1342、1343、1344 bp。共得到8种单倍型(GenBank序列号为MG786481~MG786483,MG786485~MG786487,KC292935,KC292936)。使用Mega 6.0软件计算出5个群体的组内及组间遗传距离,并构建邻接系统树。线粒体DNA D-loop及邻近区段、单独D-loop区段的碱基序列分析结果表明,单倍型Ⅰ至Ⅳ为欧洲血统,碱基差异位点数较多,变异程度较高;单倍型Ⅴ至Ⅷ为亚洲血统,碱基差异位点数较少,变异程度较低。在线粒体DNA D-loop及邻近区段内,德国镜鲤组内平均遗传距离为0.00462,核苷酸多样性指数为0.00458,平均核苷酸差异性为6.150,遗传多样性最大;州河鲤组内的平均遗传距离为0.00065,核苷酸多样性指数为0.00065,平均核苷酸差异性为0.870,遗传多样性最低。  相似文献   

9.
我国五大淡水湖日本沼虾线粒体COI基因部分片段序列比较   总被引：11，自引：1，他引：10  
对我国五大淡水湖日本沼虾100个野生个体的线粒体细胞色素氧化酶亚基I(COI)部分序列进行了测定和分析,经比对获得578 bp核苷酸片段,发现49个变异位点,得到35个单倍型,包括7个共享单倍型,各群体都具有较好的单倍型多态性和核苷酸多态性,其中鄱阳湖群体遗传多样性相对最高.AMOVA分析表明,五群体间总遗传分化系数Fst=0.3187(P<0.05),群体间具有较高的遗传分化.MEGA3.1软件计算五群体的Kimura 2-paramter遗传距离,洞庭湖群体和巢湖群体之间的遗传距离最远为0.0191,巢湖群体和洪泽湖群体之间的遗传距离最近为0.0051.以同属胖掌沼虾(Macrobrachium inflatum)为外群分别构建了NJ和UPGMA系统树,结果显示洞庭湖和鄱阳湖为一族群,太湖、巢湖和洪泽湖为一族群.  相似文献   

10.
采用形态学分析(壳长、壳宽和壳高)和分子标记技术(细胞色素氧化酶Ⅰ基因,COⅠ)对洪泽湖河蚬(Corbicula fluminea)黄色和黑色2个群体的形态和遗传多样性特征进行研究.形态参数统计分析结果显示,2个群体的形态特征之间有显著性差异.经PCR扩增和序列测定,获得614 bp COⅠ基因序列,2个群体的COⅠ基因序列的碱基组成高度一致,均表现出A+T的含量(64.8％)明显高于G+C的含量(35.2％).28个黑色个体发现7种单倍型,单倍型多样性和核苷酸多样性分别为0.794和0.04274;30个黄色个体发现5种单倍型,单倍型多样性和核苷酸多样性分别为0.607和0.02825.单倍型之间的遗传距离在0.002-0.091之间,其NJ和MP系统发生树表明,COⅠ基因单倍型聚为2个明显分支.分子方差分析(AMOVA)结果显示,Fst=0.21736 (P＜0.01),21.74％的变异来自群体间,78.26％的变异来自群体内,2个群体之间有显著的遗传分化.研究表明,应将洪泽湖河蚬黑色和黄色群体分别作为独立单元进行管理和保护.  相似文献   

11.
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.
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13.
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   

14.
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   

15.
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.  相似文献   

16.
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   

17.
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   

18.
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19.
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg.  相似文献   

20.
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   

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