4种壳色马氏珠母贝遗传规律研究

以黑、白、红、黄4种壳色马氏珠母贝选育系F6代为亲本,选取4种壳色最纯的雌雄个体各1个,采用解剖授精法和双列杂交的方法繁育子代,建立了6个杂交组合,包括4个自交组及12个正反交组。结果表明,马氏珠母贝壳色由背景色基因和前景色基因共同表达而成,位于不同的基因位点上;经过连续7代选育的4种壳色纯化度较高,壳色可以稳定遗传给下一代,其遗传规律比较复杂。黄色和白色为马氏珠母贝的背景色,白壳色贝存在母系遗传,若为隐性纯合含致死基因,黄色相对白色为显性;黑色和红色为马氏珠母贝前景色,相对无前景色为显性,黑色与红色共显。     

马氏珠母贝4种壳色家系遗传差异的SSR分析

采用6对微卫星分子标记,分析了马氏珠母贝(Pinctada martensii)白、黑、黄、红4种壳色家系的遗传结构。结果表明:4种壳色家系在6个位点的平均等位基因数为4.17,有效等位基因数为1.297~1.819;平均观测杂合度为0.083~0.212,平均期望杂合度为0.207~0.341;Shannon多样性指数为0.366~0.616;平均多肽信息(PIC)含量为0.257~0.442;4个壳色家系哈-温平衡指数均发生了极显著的偏离,4个家系间的群体再分效应的固定指数FST值为0.113~0.793;与马氏珠母贝普通养殖群体及壳色选育系F5相比,4种壳色家系之间遗传距离变大,遗传多样性降低。     

温度和盐度对4种壳色马氏珠母贝谷胱甘肽过氧化物酶基因表达的影响

谷胱甘肽过氧化物酶(GPX)基因表达可反映生物对环境压力的抗逆能力。采用中心复合设计和响应曲面分析法研究不同温度(18~34℃)、盐度(20~40)对4种壳色马氏珠母贝GPX基因表达量的影响。结果表明,马氏珠母贝4种壳色群体GPX基因表达量随着温度和盐度的升高,呈现先降低后升高的趋势。温度的一次、二次效应对4种壳色马氏珠母贝GPX基因表达的影响有统计学意义(P0.01)。盐度的一次效应仅对黑壳色马氏珠母贝GPX基因表达影响有统计学意义(P0.05);盐度的二次效应对白壳色马氏珠母贝GPX基因表达的影响有统计学意义(P0.05),对黑、红、黄壳色马氏珠母贝GPX基因表达的影响有统计学意义(P0.01)。温盐协同效应对黑、红、黄壳色马氏珠母贝GPX基因表达的影响有统计学意义(P0.05),且温度的效应大于盐度效应。经响应曲面分析法和优化,得到马氏珠母贝的GPX基因表达量在适宜的温度、盐度范围内呈峰值变化,白、黑、红、黄等4种壳色马氏珠母贝分别在(21.4℃,30.1)、(24.8℃,28.5)、(25.2℃,30.5)、(25.1℃,29.7)等温盐度组合条件下达到最优(低)值(0.072、0.065、0.057、0.078),满意度分别为100%、100%、97%、100%。所建立回归模型方程的决定系数R2范围为0.971 3~0.995 8,校正决定系数R2范围为0.942 6~0.991 5,预测决定系数R2范围为0.713 9~0.968 0,模型拟合度高,模型恰当,可用于预测温度、盐度对4种壳色马氏珠母贝GPX基因表达量的影响。     

马氏珠母贝早期生长性状的遗传参数估计

以马氏珠母贝选育系F6代为亲本,采用巢式设计方法和人工解剖授精技术,依照1雄配3雌的原则,建立了8个父系半同胞家系和24个母系全同胞家系,在第8、21、35和50天测定了每个母系全同胞个体的壳长和壳高,以全同胞组内相关分析法估计马氏珠母贝早期生长性状的遗传参数。结果表明,母系半同胞个体具有较大的变异程度,存在着较大的母性效应,父系半同胞组内相关分析法估算的狭义遗传力是马氏珠母贝遗传力的估计值。8-50日龄壳长狭义遗传力估计值为0.11~1.14,壳高狭义遗传力估计值为0.12~1.04,其中利用父系半同胞组内相关法估计壳长的遗传力依次为0.17、0.19、0.12、0.11,壳高的遗传力依次为0.20、0.23、0.13、0.12,属于中等遗传力。马氏珠母贝早期生长性状的遗传相关和表型相关表现为一定的正相关,相关系数的范围分别为0.528~0.746和0.747~0.921。在早期生长阶段以壳长或壳高为参数进行选择育种时,具有较大的遗传改良潜力。     

马氏珠母贝选系F_2早期选择反应和现实遗传力估计

对马氏珠母贝基础群体进行持续选择建立选系F2,比较了选系F2与对照群体早期生长差别,并估计了选择反应和现实遗传力。结果表明,在第8、14、21和35天,选系F2的平均壳长显著大于对照群体(P<0.05)。在第8、14、21和35天,选择反应和现实遗传力变化范围分别为0.63～0.89和0.36～0.51。本研究表明利用群体选择可以明显改良马氏珠母贝养殖群体的生长性状。     

马氏珠母贝生长性状与珍珠质量和珍珠层厚度的相关分析

以马氏珠母贝快速生长选系F3为材料,以常规技术插核操作并进行海区养殖,育珠期结束,测量育珠母贝的壳长、壳高、壳宽、总质量与壳质量共5个生长性状指标,以及商品珍珠质量与珍珠层厚度,分析育珠贝生长性状指标与珍珠层厚度及珍珠质量的相关性。结果表明:马氏珠母贝的生长性状与珍珠层厚度及珍珠质量均存在极显著相关性(p值<0.01);壳长、壳高、壳宽、总质量、壳质量与珍珠层厚度的相关系数分别为0.481、0.412、0.418、0.457、0.456;壳长、壳高、壳宽、总质量、壳质量与珍珠质量的相关系数分别为0.467、0.468、0.380、0.556、0.644。通过改良马氏珠母贝养殖群体的生长性状能够有效提高珍珠的质量。     

湛江北部湾马氏珠母贝红壳色选育系生长模型研究

为检验不同模型对马氏珠母贝红壳色选育系的生长发育拟合效果,分别采用von Bertalanffy、Gompertz、Logistic和Brody 4种非线性生长模型对红壳色选育系壳长、壳宽、壳高等形态性状和重量性状的生长发育进行拟合,通过Levenberg-Marquardt迭代法求出模型中各生长参数,结合各参数的最优值,得出拟合效果最佳的生长模型。结果表明,在马氏珠母贝红壳色选育系的第一年半生长过程中,Brody模型为壳长、壳宽与壳高的最优生长模型,von Bertalanffy模型为体重的最优生长模型,分别有效地拟合了马氏珠母贝红壳色选育系早期生长发育的累积生长曲线。     

马氏珠母贝Perlucin基因序列特征及其SNP与耐低温性状的关系

【目的】克隆马氏珠母贝（Pinctada fucata martensii）新的凝集素分子基因,命名为Perlucin,研究在低温胁迫下马氏珠母贝Perlucin的表达以及与抗低温性状相关的单核苷酸多态性（SNP）位点。【方法】根据马氏珠母贝基因组中Perlucin基因序列设计引物,克隆Perlucin基因全长;用生物信息学方法分析Perlucin的结构和理化特征;设计17和22℃（对照）2个温度组,对马氏珠母贝进行低温胁迫实验,用实时荧光定量PCR检测低温胁迫下Perlucin表达量的变化;筛选和比较分析马氏珠母贝耐低温选育系（R）F3和北部湾野生群体（W）的Perlucin外显子区的SNP位点和单倍型。【结果】马氏珠母贝Perlucin全长631 bp,编码152个氨基酸;包含1个信号肽和1个C型凝集素结构域。同源分析表明,马氏珠母贝Perlucin与紫贻贝（Mytilus galloprovincialis）Perlucin的亲缘性最近。Perlucin在鳃中表达量最高,其次为足和肝胰腺。低温胁迫时,鳃组织中Perlucin基因在17℃低温组的表达量呈先升高后降低的趋势,在12 ...     

马氏珠母贝细胞周期分裂基因CDC45基因特征、表达量与性状相关分析

采用RACE技术克隆了马氏珠母贝细胞周期分裂基因45(Pm-CDC45)全长序列,利用荧光定量PCR检测该基因在闭壳肌、鳃、性腺与外套膜组织的表达量,并估计基因表达量与金黄壳色第3代选育群体壳高性状的相关性。结果表明:Pm-CDC45基因序列全长为2 091 bp,5′非编码区(5′UTR)为157 bp,3′非编码区(3′UTR)为34 bp,其中开放阅读框为1 967 bp,编码655个氨基酸;Pm-CDC45在各组织的相对表达量存在显著差异(P0.05),其中闭壳肌表达量最高,鳃和性腺为其次,外套膜最低;Pm-CDC45基因相对表达量与选育群体壳高性状与存在显著的正相关(r=0.531,P0.05);马氏珠母贝Pm-CDC45为影响壳高性状基因。     

马氏珠母贝壳长生长模型研究

以Cp统计量作为确定马氏珠母贝壳长最优生长模型的准则,通过Levenberg-Marquardt迭代法求出模型中各生长参数,用Brody、von Bertalanffy、Gompertz、Logistic和Richards 5个生长模型对马氏珠母贝壳长的生长进行了拟合。结果表明,在马氏珠母贝生长的第一年中,壳长生长过程遵循Brody生长模型,其壳长生长极限值为56.572 mm(43.807～69.337,95%置信区间)。     

大口黑鲈选育群体遗传结构的微卫星分析

采用微卫星标记技术分析不同世代大口黑鲈选育群体的遗传结构。利用11对微卫星引物对大口黑鲈第2～4代选育群体及南水群体(对照)共120个个体进行PCR扩增,共得到28个等位基因。每个位点获得2～3个等位基因,平均等位基因为2.54。第2代(F_2)、第3代(F_3)、第4代(F_4)及南水群体(CG)的平均多态信息含量(PIC)值分别为:0.423、0.419、0.386、0.366。与F_2相比,F_4的遗传多样性减少8.76%,但与CG相比,F_4仍具有较高的遗传多样性,表明大口黑鲈选育群体的遗传基础逐步趋向纯化,且仍有较大选育潜力。此外,尽管F_2与F_4的遗传距离(0.022)比F_2与F_3的(0.011)大,但世代间的F_(st)值(0.006～0.009)均小于0.05,且世代群体总遗传分化指数为0.013,表明选育群体已出现遗传分化,但分化程度较低。     

Mass Selection for Fast Growth in the Third Generation of the Orange Line of the Manila Clam Ruditapes philippinarum

The Manila clam Ruditapes philippinarum is natively distributed along the Pacific coast of Asia, where it is one of the most important bivalve species for local fisheries. This species has been intentionally introduced due to its high adaptability to various coastal environments and is currently widely cultivated in Europe and North America. We have initiated a selective breeding program to improve the growth rate of the Manila clam since 2007, and a full-sib family with orange shell color was selected. This family features high survival but slow growth. Thereafter, two generations of mass selection were conducted in this family by 10% upward selection for faster growth. In 2011, three types of lines were produced by selecting the breeder from the second-generation of selected lines. These lines are SS(subject to three generations of selection for growth in shell length), SC(selected for the second but not the third generation), and C(randomly sampled individuals from the national population). The genetic parameters of the shell length including hR2(realized heritability), SR(selection response), and GG(genetic gain) were analyzed. Results showed that the shell length of the SS line was significantly larger than those of the SC and C lines at all developmental stages(P 0.05). For the larval stage, the values of hR2, SR, and GG were 0.42, 0.73, and 6.66, respectively. For the juvenile stage, the values of hR2, SR, and GG were 0.40, 0.69, 21.76, respectively. For grow-out stage, the values of hR2, SR, and GG were 0.48, 0.83, and 18.22, respectively. The results of hR2 indicated the good potential of the SS line in selective breeding. The level of GG improvement was encouraging and consistent with the previous expectations. No inbreeding depressions in the shell length were observed in the SS and SC lines at all sampling days. All of the results indicate that maintaining selection pressure in successive generations may be effective in the selective breeding program of this family.     

华贵栉孔扇贝两种壳色群体生长和消化酶活力比较

以华贵栉孔扇贝桔黄和紫褐壳色个体为亲本建立两个壳色群体,从壳长、壳高、壳宽和体重几方面进行生长比较,并对两个群体做了淀粉酶和纤维素酶活力比较。结果表明:桔黄壳色群体的平均壳长、平均壳高、平均壳宽和平均体重显著大于紫褐壳色群体(P<0.05)。在24℃、27℃、30℃和33℃条件下,桔黄壳色群体的淀粉酶和纤维素酶活力显著高于紫褐壳色群体(P<0.05);不同壳色群体生长与其淀粉酶和纤维素酶活力有关。     

马氏珠母贝黄壳色选系F1和养殖群体形态性状比较

<正>马氏珠母贝(Pinctada martensii)是我国南方养殖的一种重要经济贝类,长期以来一直是我国主要的海水育珠的主要贝类,用马氏珠母贝育珠是广东、广西和海南沿海部分地区经济发展的支柱性产业。近年来,我国海水珍珠的质量出现明显滑坡,严重地削弱了在国际市场上的竞争力。为提高海水珍珠质量和在国际市场上的竞争力,国内科技工作者已经进行了大量的研究工作,这些工作主要包括对马氏珠母贝养殖群体性状的改良、育珠技术的优化和海水珍珠形成机理的研究[1-5]。     

The loss of genetic diversity during captive breeding of the endangered sculpin, Trachidermus fasciatus, based on ISSR markers: implications for its conservation

Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population (the percentage of polymorphic loci PPL = 73.80%, Nei’s gene diversity h = 0.178 2, Shannon information index ...     

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。     

Molecular identification and population differentiation of Aurelia spp. ephyrae in sea cucumber aquaculture ponds of northern China

Aurelia spp. ephyrae have been reported to form blooms in sea cucumber aquaculture ponds in the Bohai and Yellow Seas. To identify the species, we carried out a genetic analysis of Aurelia spp. ephyrae and medusae based on mitochondrial 16 S rRNA gene. Samples offour Aurelia sp. ephyrae populations were collected in sea cucumber aquaculture ponds and samples offour Aurelia sp. medusae populations were collected in coastal waters. Using a BLASTn search, we found that both the ephyrae collected in the aquaculture ponds and medusae collected in coastal waters belong to Aurelia coerulea. Seventeen haplotypes were recovered from the 16 S rRNA gene. The overall haplotype diversity and nucleotide diversity of the 166 A. coerulea individuals were 0.686% and 0.329%, respectively, indicating high haplotype diversity and low nucleotide diversity. Moreover, the haplotype diversity of ephyrae populations were generally lower than that of medusae populations with close sampling points. The genetic differentiation between ephyrae populations collected in the sea cucumber aquaculture ponds and A. coerulea medusae collected in coastal waters was not significant, suggesting the ephyrae populations in the sea cucumber culture ponds were part of the same genetic group as the medusae populations in the coastal waters. Phylogeographic analysis of the 16 S rRNA region revealed that there was no significant correlation between the haplotypes and the geographic distribution of populations. Pairwise fixation index values showed significant genetic differentiation and limited gene flow between A. coerulea population of Weifang and other locations.     

胡子鲇3个养殖群体遗传结构的AFLP分析

应用AFLP方法,从64对引物中筛选出5对用于分析胡子鲇(Claris fuscus)厦门(XM)、江门(JM)、玉林(YL)等3个养殖群体共90个个体群体内、群体间遗传多样性。扩增共得到289条清晰谱带,引物多态性介于47.8%～63.8%,平均多态性比率为56.4%。胡子鲇群体总遗传杂合度(Ht)、遗传分化系数(Hs)、遗传分化度(Gst)和基因流(Nm)分别为0.161 1、0.153 6、0.051 1和8.501 8,表明胡子鲇多态性处于中等偏下水平,群体内部遗传分化系数较高,三个群体间无较大分化,群体间基因流动较好。其中,JM群体多态性比率、有效等位基因数Ne、Nei’s指数和Shannon指数都较XM群体和YL群体高,种内分化程度较好。对群体进行两两比较发现,XM群体和YL群体间分化程度最大,XM群体和JM群体次之,JM群体和YL群体最小。基于杂交优势,推断XM和YL群体繁殖所产生的后代将具有比亲代更为优良的性状。     

GENETIC DIVERSITY OF THE WILD AND REARED PSEUDOSCIAENA CROCEA

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