南海海域4种笛鲷的微卫星DNA分析

摘要：采用聚丙烯酰胺凝胶电泳技术，从20对西大西洋笛鲷（Lutjanus campechamus）的微卫星引物中筛选适用于红鳍笛鲷（L．erythopterus）、勒氏笛鲷（L.russellii）、紫红笛鲷（L.argentimaculatus）和约氏笛鲷（L.johnii）基因组分析的微卫星引物，分析4种笛鲷的遗传多样性及系统发生。经反应条件的优化，从20对引物中筛选出17对可稳定扩增出特异片段的引物。通过测序证实扩增产物含微卫星位点后，以该17对引物对4个种的群体进行遗传多样性分析。其中16对可在约氏笛鲷、勒氏笛鲷、紫红笛鲷基因组中扩增出重复性好的特异性条带，分别有65％、65％、60％呈现出种内多态：15对可在红鳍笛鲷中扩增出重复性好的特异性条带，并且全部呈现出种内多态。四种笛鲷中，红鳍笛鲷的多态性最高，高度多态基因座占检测座位的66．67％；勒氏笛鲷的多态性最低，低度多态基因座占43．75％。获得3个种间特异性分子标记。用风和DA两种方法计算4种笛鲷的遗传距离，构建了系统发生树。     

三种笛鲷属鱼类的随机扩增多态性DNA初步研究

RAPD技术是由 Williams[1]和 Welsh[2 ]领导的两个科研小组于 1 990年几乎同时独立创立的一种 DNA多态性分析技术 ,它的原理是利用一系列随机排列的寡核苷酸单链引物 ,以研究对象的基因组 DNA为模板进行 PCR扩增 ,通过扩增产物 DNA片段的多态性来检测基因组 DNA的多态性。该技术已被广泛地应用于种质鉴定、遗传多样性、亲缘关系及系统分类研究 [3～ 6]。但对海水鱼类RAPD研究报道较少。红鳍笛鲷 (L utjanus erythopterus Bloch)、紫红笛鲷 (L utjanus argentimaculatus Forskal)和勒氏笛鲷 (L utjanus russelli Bleeker)具有…     

紫红笛鲷随机扩增多态性DNA及遗传多样性分析

采用RAPD技术分析了湛江近海紫红笛鲷 (LutjanusargentimaculatusForsk l)的遗传多样性。从 12 0个随机引物中筛选出了 14个引物。 14个引物共检测到 173个位点 ,其中多态位点比例 (P)为 6 8.79%,遗传距离 (D)为 0 .2 2 2 8,遗传多样性指数 (H)为 0 .190 4。结果表明 ,目前湛江近海的紫红笛鲷自然群体的遗传多样性仍然维持在良好水平 ,捕捞尚未对其造成明显影响。     

紫红笛鲷随机扩增多态性DNA及遗传多样性分析

采用RAPD技术分析了湛江近海紫红笛鲷(Lutjanus argentimaculatus Forskal)的遗传多样性。从120个随机引物中筛选出了14个引物。14个引物共检测到173个位点，其中多态位点比例(P)为68．79％，遗传距离(D)为0．2228，遗传多样性指数(日)为0．1904。结果表明，目前湛江近海的紫红笛鲷自然群体的遗传多样性仍然维持在良好水平，捕捞尚未对其造成明显影响。     

运用RAPD技术对笛鲷属3种鱼的群体遗传学分析

应用RAPD技术，从9个系列180种随机引物中筛选出16种，对笛鲷属的画眉笛鲷(Lutja-nus vitta）、金焰笛鲷(Lutjanus fulviflamma)_，金带笛鲷(Lutjanus vaigiensis)进行种群内及种群间遗传学分析，并利用UPGMA确定了它们之间的亲缘关系。结果表明，三种鱼的种内遗传多样性指数(H)分别为，画眉笛鲷0．1949，金带笛鲷0．1107，金焰笛鲷0．1673；三者的多态位点比例(P)分别为69．4％、47．8％和59．0％；金带笛鲷具有较低的遗传多样性，且金带笛鲷与金焰笛鲷有较近的亲缘关系。三种鱼共检出10个可作为种的特异性鉴定的条带，可用于种质鉴定。     

两种体色画眉笛雕的遗传多样性及分子标记

根据体侧纵带颜色差异,暂将画眉笛鲷(Lutjanus vitta)分为黄带画眉笛鲷和褐带画眉笛鲷,应用RAPD技术,选用22个引物对黄带画眉笛鲷与褐带画眉笛鲷进行遗传多样性及分子标记研究。结果表明,黄带画眉笛鲷与褐带画眉笛鲷的遗传距离为0.832 9,其多态位点比例(P)分别为66.99%和85.28%,遗传多样性指数(H)分别为0.161 7和0.289 3,种内遗传距离(D)分别为0.243 5和0.431 9,表明褐带画眉笛鲷的遗传多样性比黄带画眉笛鲷丰富。共得到OPP14-629bp和OPP14-674bp等11个特异性分子标记,可用于两种笛鲷的鉴定。     

RAPD分析中最适样本量和位点数的研究

用25个引物,对40个样本扩增,研究了勒氏笛鲷随机扩增多态性DNA(RAPD)分析中的最适样本量和位点数。结果显示:在样本量达到20且位点数达到70个以上时,遗传距离趋于一个稳定的数值,即在RAPD分析中,样本数应达到20且位点数应达到70才能保证结果的可靠性。     

RAPD分析中最适样本量和位点数的研究

用25个引物，对40个样本扩增，研究了勒氏笛鲷随机扩增多态性DNA（啪）分析中的最适样本量和位点数。结果显示：在样本量达到20且位点数达到70个以上时，遗传距离趋于一个稳定的数值，即在RAPD分析中，样本数应达到20且位点数应达到70才能保证结果的可靠性。     

红鳍笛鲷和紫红笛鲷种类和群体的矢耳石地标点法识别

【目的】探讨矢耳石地标法在笛鲷种内及种间中的判别作用。【方法】利用2017年购自广西北海、海南文昌、广东阳江的87尾红鳍笛鲷(Lutjanus erythropterus)和76尾紫红笛鲷(Lutjanus argentimaculatus)成鱼的矢耳石样本,基于地标点法分析耳石的形态差异,运用判别分析检验耳石形态差异在2种笛鲷的种间和同种不同群体间的判别功效。【结果】位于听沟前中部交叉点的两个地标点10、11贡献较大,解释了耳石形态变异的64.88%～65.85%,表明两种笛鲷耳石形态的种间差异和种内群体差异主要集中于听沟前中部。基于耳石形态的地标点方法对2种笛鲷的种间判别成功率为97.4%和100.0%;红鳍笛鲷和紫红笛鲷的种内不同群体判别成功率分别为85.7%、83.3%、80.0%和94.1%、78.1%、81.5%。【结论】矢耳石地标点法可作为2种笛鲷种间和种内判别的有效工具。     

红鳍笛鲷微卫星DNA标记的开发与遗传多样性分析

以三亚外海的红鳍笛鲷(Lutjanus erythropterus)自然群体为研究对象,利用磁珠富集法开发19个适用于红鳍笛鲷的微卫星DNA标记,其中16个为多态性标记,等位基因数为2～11,期望杂合度为0.242～0.896,观测杂合度为0.156～1.000,Ler 14、Ler 29、Ler 49等3个位点偏离哈迪-温伯格平衡(P<0.0031),Ler9-Ler18、Ler12-Ler19、Ler46-Ler47、Ler46-Ler49、Ler18-Ler50、Ler14-Ler51等6对位点间检测到明显的连锁(P<0.05),Ler29、Ler13、Ler49、Ler19、Ler24、Ler25、Ler14、Ler51、Ler18、Ler9等10个位点属于高度多态位点[多态信息含量(PIC)>0.5],Ler47、Ler12、Ler15、Ler46等4个为中度多态位点(0.25>PIC>0.5)。     

运用RAPD技术对笛鲷属3种鱼的群体遗传学分析

应用RAPD技术,从9个系列180种随机引物中筛选出16种,对笛(鱼周)属的画眉笛(鱼周)(Lutja-nus vitta)、金焰笛(鱼周)(Lutjanus fulviflamma)、金带笛(鱼周)(Lutjanus vaigiensis)进行种群内及种群间遗传学分析,并利用UPGMA确定了它们之间的亲缘关系。结果表明,三种鱼的种内遗传多样性指数(H)分别为,画眉笛(鱼周)0.1949,金带笛(鱼周)0.1107,金焰笛(鱼周)0.1673;三者的多态位点比例(P)分别为69.4％、47.8％和59.0％;金带笛(鱼周)具有较低的遗传多样性,且全带笛(鱼周)与金焰笛(鱼周)有较近的亲缘关系。三种鱼共检出10个可作为种的特异性鉴定的条带,可用于种质鉴定。     

军曹鱼全人工繁殖群体遗传特征的SSR分析

利用8个微卫星DNA位点分析南海海域5个军曹鱼全人工繁育群体(HN1、HN2、ZJ、FJ和LS)子代的遗传多样性特征和群体间遗传分化。结果显示,军曹鱼养殖群体与天然群体的遗传结构特征基本一致:1)平均有效等位基因数为3.910±0.440,观测杂合度为0.595±0.049,分子方差分析(AMOVA)表明,个体内分化占主导(46%),军曹鱼养殖群体整体遗传多样性较高;2)群体间基因流明显(N_m=2.5959,F_(st)=0.0878),整体分化程度较低。各养殖群体表现出不同于天然大群体的特征:1)绝大部分位点均明显偏离哈温平衡,杂合子缺失或过剩现象普遍存在;2)聚类和群体分配分析等表明HN2与另四个养殖群体(HN1、ZJ、FJ和LS)分化明显。     

Analysis of genetic diversity and differentiation of seven stocks of Litopenaeus vannamei using microsatellite markers

Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.     

广东流沙湾网箱养鱼区水体氮磷的时空变化及负荷估算

研究流沙湾网箱养鱼区水体氮、磷含量的月变化和水平分布,并运用质量平衡方程估算其氮、磷负荷。结果表明:总氮变化在0.212~0.892 mg/L之间,平均0.498 mg/L;总磷变化在0.009~0.036 mg/L之间,平均0.020mg/L;氮磷比变化在23.6~26.1之间,平均为25。在5-9月,氮、磷含量变化呈逐渐增加趋势,到9月达到最大,10月又减少。网箱内部氮、磷的含量高于网箱外部,并随着与网箱距离的增大而逐渐减小。红鳍笛鲷(Lutjanus argentimaculatus)、紫红笛鲷(Trachinotus ovatus)和卵形鲳鲹(Lutjanus erythopterus)全鱼的氮质量分数平均为2.42%,磷质量分数平均为0.26%,饵料系数为6.67,流沙湾网箱养鱼养殖期产生的氮、磷负荷平均分别为135.8和19.4 kg/t。     

AFLP analysis of genetic variation among three natural populations of horseshoe crab Tachypleus tridentatus along Chinese coast

The AFLP(amplified fragment length polymorphism) technique was used to analyze and compare the genetic diversity of Tachypleus tridentatus from three south-eastern coastal sites of China(Pingtan,Hong Kong and Beihai).Eight pairs of primers generated 361 loci,including 285 polymorphic loci.The ratio of polymorphic loci was 96.97%.Nei's genetic diversity index was 0.420 8 and the Shannon information index was 0.607 5,both of which were higher than that reported for many other arthropods.These results show tha...     

Genetic diversity in two Japanese flounder populations from China seas inferred using microsatellite markers and COI sequences

Japanese flounder is one of the most important commercial species in China; however, information on the genetic background of natural populations in China seas is scarce. The lack of genetic data has hampered fishery management and aquaculture development programs for this species. In the present study, we have analyzed the genetic diversity in natural populations of Japanese flounder sampled from the Yellow Sea (Qingdao population, QD) and East China Sea (Zhoushan population, ZS) using 10 polymorphic microsatellite loci and cytochrome c oxidase subunit I (COI) sequencing data. A total of 68 different alleles were observed over 10 microsatellite loci. The total number of alleles per locus ranged from 2 to 9, and the number of genotypes per locus ranged from 3 to 45. The observed heterozygosity and expected heterozygosity in QD were 0.733 and 0.779, respectively, and in ZS the heterozygosity values were 0.708 and 0.783, respectively. Significant departures from Hardy-Weinberg equilibrium were observed in 7 of the 10 microsatellite loci in each of the two populations. The COI sequencing analysis revealed 25 polymorphic sites and 15 haplotypes in the two populations. The haplotype diversity and nucleotide diversity in the QD population were 0.746±0.072 8 and 0.003 34±0.001 03 respectively, and in ZS population the genetic diversity values were 0.712±0.047 0 and 0.003 18±0.000 49, respectively. The microsatellite data (F_st =0.048 7, P<0.001) and mitochondrial DNA data (F_st =0.128, P<0.001) both revealed significant genetic differentiation between the two populations. The information on the genetic variation and differentiation in Japanese flounder obtained in this study could be used to set up suitable guidelines for the management and conservation of this species, as well as for managing artificial selection programs. In future studies, more geographically diverse stocks should be used to obtain a deeper understanding of the population structure of Japanese flounder in the China seas and adjacent regions.     

基于近缘EST-SSR引物的企鹅珍珠贝养殖和野生群体的遗传标记

利用近源物种马氏珠母贝的EST-SSR引物对企鹅珍珠贝DNA进行扩增,获得7对可扩增出目标条带的近缘分子标记,分析野生群体(YS)和养殖群体(YZ)企鹅珍珠贝的遗传多样性。结果显示,7个位点共获得26个等位基因;野生和养殖群体的等位基因数分别为3~5和3~4,平均期望杂合度(He)分别为0.623 5、0.496 8;平均观测杂合度(Ho)分别为0.431 8、0.302 8;HNUPM047位点的多态信息含量较低,为0.446 7,其他位点均在0.5以上,说明该遗传标记可提供比较丰富的遗传信息。表明养殖群体遗传多样性水平低于野生群体。