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1.
秦皇岛海域野生牙鲆群体遗传多样性分析   总被引：2，自引：0，他引：2  
用18对多态性微卫星标记对采自秦皇岛海域的90尾野生牙鲆(Paralichthys olivaceus)进行遗传分析。18个微卫星位点共检测出161个等位基因;各位点等位基因数为7~11个,平均为8.9;有效等位基因为3.7~8.0,平均有效等位基因为5.9;各个位点多态信息含量为0.69~0.86,平均值为0.80;Shannon多样性指数平均值为1.9;观测杂合度(Ho)值为0.33~0.87,平均值为0.64;期望杂合度为0.74~0.89,平均期望杂合度(He)为0.84。χ2检验表明,18个位点中有9个的等位基因分布偏离了哈迪温伯格平衡(P<0.05)。研究结果表明,秦皇岛海域野生牙鲆群体遗传信息含量丰富、等位基因分布均匀,遗传多样性较高,但是,存在Hardy-Weinberg不平衡现象。  相似文献   

2.
用微卫星标记分析湘华鲮野生群体遗传多样性   总被引：1，自引：0，他引：1  
为了解湘华鲮天然种质资源现状,用38对鲤科鱼类微卫星引物对其群体进行全基因组扫描,结果筛选出15对能够获得稳定扩增条带的引物。以鲮鱼养殖群体为对照群体。在15个微卫星位点中,湘华鲮多态性位点9个,对照群体6个。通过分析湘华鲮微卫星位点PCR产物的电泳图谱,共检测到40个等位基因,每个位点的等位基因数目介于1～5之间,其平均等位基因数为2．67个,平均有效等位基因数为1．47个,平均观察杂合度为0．2289,平均期望杂合度为0．2730,平均多态信息含量（PIC）为0．2440,多数Hardy-Weinberg平衡偏离指数值偏离平衡值,与对照组无显著性差异。本研究表明湘华鲮野生种群结构不合理,遗传多样性低,种质资源处于危险状态。  相似文献   

3.
文章采用微卫星标记技术,对吉富品系尼罗罗非鱼(GIFT strain Oreochromis niloticus)抗病群体和易感病群体进行了遗传差异分析。结果显示:在30个微卫星位点中20个能扩增出多态性高、重复性好和扩增条带清晰;抗病群体和易感病群体的平均等位基因数分别为2.5和2.4个;观测杂合度和期望杂合度分别为0.476和0.453,0.44和0.457;多态信息含量PIC分别为0.359和0.379;UNH845和UNH189位点在抗病群体中偏离Hardy-Weinberg平衡(P0.05),GM180位点在易感病群体偏离Hardy-Weinberg平衡,两个群体间的遗传距离和遗传分化指数0.055和0.054。此外GM251和GM462位点的差异等位基因片段(135bp和198bp)与抗病性状存在一定的连锁关系。以上结果表明,吉富品系尼罗罗非鱼抗病群体与易感病群体之间的遗传多样性差异不明显,筛选出2个与抗病性状相关的微卫星标记,为开展吉富品系尼罗罗非鱼抗病品种分子标记辅助选育奠定了基础。  相似文献   

4.
金沙江观音岩段圆口铜鱼的微卫星遗传多样性分析   总被引：1，自引：0，他引：1  
选用10对微卫星引物,对金沙江观音岩江段圆口铜鱼(Coreius guichenoti)群体的遗传多样性进行研究。统计分析了有效等位基因数、观测杂合度、期望杂合度、多态信息含量等遗传学指标,结果显示所选用的10对微卫星引物均表现为高度多态性,共检测到等位基因数84个,平均有效等位基因数5.429 6;观测杂合度0.800 0~0.933 3、期望杂合度0.774 7~0.841 4;多态信息含量为0.649~0.753;Shannon’s指数为1.523 7~2.260 2;Hardy-Weinberg平衡偏离指数为0.032 6~0.127 7。结果表明该江段圆口铜鱼群体遗传多样性较丰富。  相似文献   

5.
应用微卫星DNA技术对仿刺参中国群体、韩国群体及其杂交后代的遗传多样性进行了研究。15对微卫星引物共扩增获得60个等位基因,平均等位基因数为4,平均有效等位基因数为2.5855。3个群体的平均观测杂合度分别为0.2965、0.3548、0.2755,平均期望杂合度为0.5296、0.5574、0.5364,多态性信息含量为0.0000~0.8480,平均值为0.4653、0.4860和0.4630。Hardy-Weinberg平衡的P值检验,发现3个群体普遍存在偏离平衡的现象。试验结果表明,15个位点中,14个位点为中度或高度多态,3个群体多样性处于中等偏上水平;韩国群体的遗传多样性水平在3个群体中最高,杂交后代并未表现出明显的杂种优势,但在某些微卫星位点观测到的等位基因频率和基因型频率表现出与亲本的差异,说明杂交过程使后代获得了一定程度的遗传分化,中国群体与韩国群体的杂交后代具一定的选育潜力。  相似文献   

6.
北部湾光裸星虫3个地理群体遗传多样性   总被引：1，自引：0，他引：1  
利用微卫星DNA分子标记对广东湛江乌石(ZJ)、广西北海山口(BH)与越南锦普(JP)3个光裸星虫(Sipunculus nudus)野生群体的遗传多样性进行分析。结果表明,20个微卫星座位中有3个位点(Snu08、Snu10、Snu14)呈现单态,17个多态微卫星座位中的等位基因数介于2～9之间,多态信息含量(PIC)介于0.097～0.797之间。每个群体中有5个位点显著偏离了Hardy-Weinberg平衡,在位点Snu18上3个群体均偏离Hardy-Weinberg平衡。3个光裸星虫野生群体均表现出中等程度的遗传多样性水平,锦普群体遗传多样性水平高于北海和湛江群体。群体间F-统计量分析表明,群体遗传分化处于低等分化水平,差异不显著(Fst=0.019～0.049,P>0.05);基于DA遗传距离构建的NJ和UPGMA聚类树均显示,地理位置相邻的群体聚在一起。研究表明,3个光裸星虫地理群体均具有中等的遗传多样性,杂合度均偏低,群体间存在较大的基因流,杂合子明显缺失;群体间已产生遗传分化,但分化水平还较低。  相似文献   

7.
利用8个微卫星标记对福建牡蛎(Crassostrea angulata)基础群体、‘金蛎1号’选育系F6和野生群体进行遗传多样性分析。结果表明,每个位点在各群体的等位基因数为7~24个,各群体在所有位点的平均等位基因数为10.3~17.6个,平均等位基因丰度为9.8~16.8。平均观测杂合度和平均期望杂合度分别为0.655~0.662和0.788~0.872。经邦弗朗尼校正,哈迪–温伯格平衡检验结果显示,在24个群体–位点组合中18个群体–位点组合显著偏离平衡(P0.01)。群体内近交系数F_(is)值介于0.0095~0.2874,平均值为0.1992,遗传分化系数F_(st)介于0.0224~0.1627,平均值为0.0767,暗示选育群体中存在较低水平的非随机交配现象,属于中度偏低分化。研究表明,连续的选育对群体的遗传分化产生了一定的影响,但是,选育群体仍然具有较高水平的遗传多样性。  相似文献   

8.
本文利用15对微卫星分子标记,对德国镜鲤选育系F4天津群体中的高背型和长条型德国镜鲤的遗传结构进行分析.结果表明:两种体型德国镜鲤F4群体平均等位基因数分别为5.0和5.1,平均期望杂合度分别为0.5527和0.5591,平均观测杂合度分别为0.5906和0.5824,平均多态信息含量分别为0.5653和0.5470.以卡方检验估计群体Hardy-Weinberg平衡显示有大部分位点发生了偏离.两体型间遗传相似性为0.8330,相似性较高.群体间遗传分化微弱(Fst=0.0242),群体内变异占总变异的97.58%.说明高背型德国镜鲤和长条型德国镜鲤在遗传结构上差异较小.由天津群体的等位基因数为5.05,期望杂合度为0.5559,观测杂合度为0.5865,多态信息含量为0.5562,可知天津群体属于中度多态,遗传多样性保持较高水平.  相似文献   

9.
利用筛选的16对微卫星标记对来自于湖南湘西龙山县乌龙山3个不同洞穴的盲高原鳅群体进行遗传多样性及遗传分化分析.通过计算多态信息含量、平均杂合度、等位基因数、遗传距离、基因流、F-统计量等参数,评估各盲高原鳅群体遗传多样性和各群体间遗传分化.16个微卫星标记在3个群体中共检测出83个等位基因.每个座位检测到3～8个等位基因不等.3个群体各个多态位点的平均观测杂合度分别为0.362 5～0.946 5,平均期望杂合度为0.538 6～0.906 5.3个群体多态微卫星位点的PIC分别为0.263 2、0.231 3、0.303 5,选取的16个微卫星位点中2个为高度多态,2个为低度多态,其余为中度多态.分子变异方差分析(AMOVA)结果表明,遗传变异大部分(92.84％)来自群体内,仅有7.16％的变异来自于群体间,数据表明3个群体处于未分化状态,遗传一致性较大.  相似文献   

10.
大泷六线鱼资源捕捞量逐渐加大,捕捞个体体型却逐渐减小,研究大泷六线鱼的遗传多样性,对提高在渔业养殖中种群质量具有重要意义。本研究利用7对微卫星分子标记对大泷六线鱼(Hexagrammos otakii)的6个地区群体(大连、丹东和青岛等地)进行了遗传多样性和遗传变异评估。结果表明,获得的等位基因数1~8,平均等位基因数6.29;有效等位基因数1.00~5.72,平均有效等位基因数4.71;各群体的杂合度观测值(Ho)为0.05~0.27;杂合度期望值(He)为0.44~0.75;多态信息含量(PIC)为0.47~0.69,说明这6个群体属于高度多态,遗传多样性水平较高。群体间遗传分化系数(F_(st))为0.27,表明6个大泷六线鱼群体之间存在明显的遗传分化。采用UPGMA法对6个大泷六线鱼群体进行聚类分析,发现大连和长海县大泷六线鱼群体亲缘关系较近且聚为一个分支,其他4个群体聚为另一分支。结合Hardy-Weinberg平衡检验分析,发现各群体表现出极显著的遗传不平衡,不符合Hardy-Weinberg平衡定律,表明6个群体大泷六线鱼遗传多样性较为丰富。综上说明,6个大泷六线鱼群体发生了较大的遗传分化,遗传多样性较为丰富。  相似文献   

11.
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12.
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   

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.
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   

15.
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   

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.
Cholecalciferol (Vitamin D3) increased plasma inorganic phosphate concentration in American eels,Anguilla rostrata, in a dose-dependent fashion. This response was more marked in phosphate loaded fish. In control as well as phosphate loaded eels the hyperphosphatemic response to D3 was associated with a sharp reduction in renal phosphate clearance relative to14C-polyethelene glycol (PEG) clearance. Glomerular filtration and urine flow rates were not affected by D3. As renal phosphate clearance, even in phosphate loaded eels, never significantly exceeded that of PEG, it is suggested that D3 reduced the relative clearance rate of phosphate by increasing renal phosphate reabsorption rather than by reducing the tubular secretion of phosphate.  相似文献   

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