基于线粒体CO1基因的DNA条形码在石首鱼科(Sciaenidae)鱼类系统分类中的应用

采用CO1基因特异扩增测序及与GenBank已有序列联配分析的方法,进行了石首鱼科19属30种鱼类75个CO1基因片段的序列比较和系统进化研究,结果表明,石首鱼科鱼类该片段的平均GC含量为48.3%,其中第2密码子位点含量最高(51%-58.4%,平均56.6%),第1密码子变化范围最大(27.6%-54.1%,平均44.9%),第3密码子差别较小(41.6%-43.6%,平均42.7%)。依据Kimura-2-parameter模型,30种石首鱼科鱼类种内遗传距离平均值为0.006,种间为0.210,种间遗传距离是种内的35倍;在分子系统树上,28个种(93.3%)可形成单系,18个属(94.7%)可聚为独立的分支;与形态学分类不同的是,由黑鳃梅童鱼(Collichthys lucidus)与棘头梅童鱼(C.niveatus)的遗传距离(0.004)推断二者遗传变异尚未达到种的分化水平,灰鳍彭纳石首鱼(Pennahia anea)与白姑鱼(Argyrosomus argentatus)的形态学特征相似性和条形码序列同源性都提示二者可能为同种异名,而红牙(Otolithes ruber)印度洋和南海两个地理群体间的遗传分化已经达到种的水平。本研究证明线粒体CO1基因可作为DNA条形码对石首鱼科鱼类进行有效的物种鉴定,亦可用于探讨石首鱼科的属、种分类单元系统发育问题。     

转基因技术在鱼类及对虾中的应用(英文)

作者对转基动物的出现背景及优点,转基因过程的基本程序,转基因鱼研究的现状,鱼类基因的大量克隆,基因启动子的快速分离技术,分析启动子活性的瞬时转基因测试,绿色荧光蛋白转基因鱼作为观赏鱼的潜力,转抗病基因的研究进展,转基因技术在对虾中应用的展望,作了较全面的叙述。     

8种石首鱼类线粒体基因组特征及分子系统进化分析

为探讨石首鱼科(Sciaenidae)鱼类分子系统进化关系,采用生物信息学方法分析了黑鳃梅童鱼(Collichthys niveatus)、棘头梅童鱼(C.lucidus)、大黄鱼(Larimichthys crocea)、小黄鱼(L.polyactis)、鮸鱼(Miichthys miiuy)、白姑鱼(Pennahia argentata)、黄姑鱼(Nibea albiflora)和皮氏叫姑鱼(Johnius belangerii)共8种石首鱼类线粒体基因组全序列的基本特征。结果显示,除皮氏叫姑鱼外,其余7种石首鱼类编码的37个基因排列顺序与脊椎动物线粒体基因组相同。基因组碱基分布存在不均衡现象,A+T含量高于G+C含量。线粒体基因组的基因变异位点分析结果表明,ND4和ND5基因可作为COI基因的辅助分子标记,应用于石首鱼类群体遗传学的研究中。黄鱼亚科5种鱼类13个蛋白质编码基因的Ka/Ks比值远低于1,显示出较强的纯化选择。皮氏叫姑鱼与其他石首鱼间的遗传距离均较大且亲缘关系较远,暗示叫姑鱼属或为石首鱼类中较为原始的类群。基于线粒体基因组全序列构建NJ系统树支持黄鱼亚科和白姑鱼亚科亲缘关系较近的形态学结论。而基于去除控制区后序列和13个蛋白质编码基因序列构建的系统树则表明两亚科鱼类间的差别在非编码区更为明显。     

浙江新昌光唇鱼(Acrossocheilus)CO Ⅱ和D-loop基因克隆及系统发育分析

采用扩增COⅡ、D-loop序列、进行序列比对和系统树分析并结合形态特征观察的方法,研究了浙江新昌光唇鱼(Acrossocheilus)的系统分类和种类鉴定。形态特征结果表明,新昌光唇鱼具有光唇鱼属鱼类的基本特征;扩增得到COⅡ序列全长691bp,D-loop序列全长931—944bp,A+T含量两基因序列都高于G+C(A+T的含量分别为57.30%—57.80%和65.30%—65.90%),G的含量在四种碱基中最低;COⅡ序列有6个碱基位点存在转换,而D-loop则存在多个碱基的转换、颠换、缺失或插入位点。浙江新昌光唇鱼群体内COⅡ、D-loop基因的平均遗传距离分别为0.003、0.005;基于COⅡ和D-loop序列构建的NJ法系统树均显示新昌光唇鱼与温州光唇鱼(A.wenchowensis)形成一个紧密的簇,序列相似性分别为99.94%和99.36%,遗传距离分别为0.000、0.011,未达到种间分化水平(遗传距离大于0.05),表明新昌光唇鱼与温州光唇鱼为同一种,且根据形态特征可以断定为二个不同的地理群体,而D-loop序列因进化速度较快更适于光唇鱼属种内及近缘物种的种间亲缘关系的研究。研究结果既有助于新昌光唇鱼资源的开发利用,又可为研究光唇鱼类的分类提供参考资料。     

基于线粒体16S rDNA和COΙ基因探讨中国近海黄姑鱼类的分子系统进化关系

为探讨中国近海黄姑鱼类的系统进化关系,通过PCR扩增了黄姑鱼(Nibea albifora)、浅色黄姑鱼(N.coibor)、日本黄姑鱼(N.japonica)和状黄姑鱼(N.miichthioides)等4种黄姑鱼类的16S rDNA和COΙ基因片段并进行了序列测定,计算其种间及种内遗传距离并结合来自GenBank的13种石首鱼科鱼类的相应基因片段序列构建分子系统树。结果表明:(1)利用16S rDNA片段可以对4种黄姑鱼类进行分子鉴定;但是基于COΙ基因片段计算的日本黄姑鱼和状黄姑鱼的种间遗传距离为0.002—0.005,尚未达到种间分化水平,应用该基因片段进行这两种鱼的分子鉴定值得商榷;(2)分子系统树显示日本黄姑鱼和状黄姑鱼与黄姑鱼和浅色黄姑鱼处于不同的系统发育阶元,日本黄姑鱼和状黄姑鱼与白姑鱼属鱼类聚为同一类群,支持形态学上将日本黄姑鱼和状黄姑鱼划归为白姑鱼属的分类学观点。     

鱼类生长激素的异源表达、应用及安全性评价

鱼类生长激素对鱼的生长发育起着重要的调节作用，能促进鱼体快速生长，提高饵料转化率，在水产养殖业中具有重大应用价值。转生长激素基因鱼具有快速生长效应，可以缩短养殖周期，降低养殖成本和风险。鱼类生长激素基因异源表达体系的建立和发展，使获得大量廉价的鱼类生长激素产品成为可能，为鱼类养殖业新型饵料添加剂的研制开辟了新的途径。本文综述了转生长激素基因鱼和鱼类生长激素基因的异源表达两方面的研究及其安全性评价。     

南极冰鱼和伯氏肩孔南极鱼EPO基因预测及生物信息学分析

运用PCR、TA克隆及二代测序技术获得了独角雪冰鱼(Chionodraco hamatus)、伯氏肩孔南极鱼(Trematomus bernacchii)的EPO区域基因组DNA序列,并结合生物信息学方法进行了基因结构与保守功能域等生物学特性研究。结果表明:克隆获得的独角雪冰鱼、伯氏肩孔南极鱼EPO基因序列分别为2727 bp和2820 bp,包括5个外显子和4个内含子结构,编码区全长皆为558 bp,推定编码185个氨基酸。理化性质分析得到两者的EPO蛋白皆为相对稳定的酸性可溶性蛋白。其三级结构预测结果都显示出典型的4个反相平行的α螺旋结构特征,保持了其在生物体内发挥的原有作用。多重序列比对显示,独角雪冰鱼EPO与伯氏肩孔南极鱼的氨基酸同源性为95.2%,而与其它物种的同源性在53.9%—85.5%之间。系统发育树显示,独角雪冰鱼、伯氏肩孔南极鱼的EPO基因与鱼类的同源基因聚类,系统进化情况同亲缘关系一致,表明EPO基因在进化过程中具有较强保守性。本研究为揭示EPO基因在南极冰鱼内的遗传特性提供理论依据,并为进一步探讨EPO基因在极端低温高氧环境中的鱼类适应性进化研究奠定了基础。     

印度-太平洋石鲈亚科鱼类DNA条形码及分子系统进化研究

为探讨DNA条形码基因COⅠ序列在石鲈亚科鱼类物种鉴定的有效性,本研究分析了印度-太平洋区域的石鲈亚科7个属29种鱼类9个个体长度为651 bp的COⅠ基因序列,利用MEGA 5.0计算石鲈亚科种内与种间的遗传距离,并基于最大简约法与最大似然法构建了其分子系统进化关系。结果显示:石鲈亚科鱼类种间遗传距离在0.021—0.240之间,平均遗传距离0.184;种内遗传距离在0.000—0.009之间,平均0.004。其中种间平均遗传距离(0.184)显著大于种内平均遗传距离(0.004),种间遗传距离是种内的46倍。同时,各物种间遗传距离均大于Hebert推荐区分物种的最小种间遗传距离0.02(2%)。基于COⅠ序列构建的系统进化树,同一物种不同个体间均能聚成独立的单系,表明COⅠ基因可作为石鲈亚科物种准确鉴定的有效条形码基因。同时,系统进化树上,石鲈属是非单系类群,主要形成5个分支,而不同分支的种类与其地理分布存在一定的相关性,与近年部分分子系统地理学的研究观点一致。     

鲑鱼生长激素基因表达产物的促生长效应

生长激素用于促进鱼类生长的研究已有几十年历史。国内外一些研究者先后用哺乳类动物和鱼类本身的生长激素，通过体内注射、投喂和注射等方式导入实验鱼体内，均获得不同程度的促进鱼类生长的效果［１，３，５，６，９］。８０年代中期，随着基因工程的发展，国外许多实验室从哺乳动物和多种鱼类中分离出生长激素基因，构建了可在工程菌中表达的重组质粒，实现了这些基因在工程菌中的高效表达和表达产物的有效分离。随后利用工程菌中表达的生长激素所进行的鱼类养殖实验表明，它们具有与天然生长激素相同的促生长效应［２，４，８］。与天然…     

基于S7核糖体蛋白基因部分序列的10种石鲈科鱼类的系统发育关系

分析了石鲈科4属10种鱼类S7核糖体蛋白基因内含子1部分序列特征,采用MP法和NJ法构建系统发育树.结果表明,在分子系统树上,10种石鲈科(Haemulidae)鱼类共组成两大类群,其中髭鲷属(Hapalogenys)鱼类和胡椒鲷属(Plectorhynchus)鱼类聚成一类群,石鲈属(Pomadasys)鱼类和仿石鲈属(Haemulon)鱼类聚成一类群,两类群再聚成一支,10种石鲈科鱼类构成单一分支类群.髭鲷属鱼类跟胡椒鲷属鱼类的亲缘关系较近.基于遗传距离分析表明,相对于石鲈属,髭鲷属鱼类跟仿石鲈属鱼类的遗传距离较小.因此,研究结果支持髭鲷属的分类地位是介于胡椒鲷属和仿石鲈属之间,未能从石鲈科中独立出来形成髭鲷科(Hapalogeniidae).     

鱼生长激素在水产养殖中的应用

鱼生长激素是鱼类脑垂体中分泌的促进生长的单一亚基的蛋白激素.它参与鱼的生长代谢，能够加速蛋白质合成和脂类降解等生理功能.鱼生长激素能够大大地加快鱼类的生长，在鱼类的水产养殖领域有重大的应用价值，日益引起了人们的关注.现阶段鱼生长激素的应用研究主要集中在转生长激素基因鱼的育种和鱼生长激素的基因工程表达两个方面，且都取得了很大的进展.     

双锯鱼(Amphiprion)胚胎不同发育阶段和成鱼不同组织中内参基因的筛选及应用

双锯鱼(Amphiprion)亦称为海葵鱼,又称为小丑鱼,是一类经济价值较高的海水观赏鱼。目前国内在双锯鱼的胚胎发育、人工饲养以及形态学观察等方面已经取得了有效成果,但在分子生物学水平上对其基因表达的研究较少。为了筛选出适用于双锯鱼胚胎不同发育阶段以及成鱼组织的内参基因,分析酪氨酸酶(TYR)基因的表达情况,以眼斑双锯鱼(A.ocellaris)和白条双锯鱼(A.frenatus)为材料,利用实时定量聚合酶链式反应(qPCR)对18SrRNA、GAPDH(甘油醛-3-磷酸脱氢酶基因)、Ef-1α(转录延伸因子基因)和β-actin(β-肌动蛋白基因)这4个候选内参基因的表达水平进行检测,同时通过geNorm和Norm Finder软件对其稳定性进行评估,最后以合适的内参基因作为参考,研究TYR mRNA的表达水平。结果表明,在双锯鱼胚胎的不同发育阶段,18S和β-actin的表达量相对于其他基因较为稳定;在双锯鱼的不同组织中,稳定性依次为18S>β-actin>Ef-1α>GAPDH。以18S作为内参基因时分析发现TYR基因的表达在双锯鱼胚胎发育过程中呈先上升后下降的趋势,在体节期表达量最高;在双锯鱼各组织中均有表达,且在眼、尾和红皮中表达量最高。     

Some experiments and considerations for development of Doppler-based riverine sonars

Sonar counting devices have been utilized by fisheries biologists to estimate annual spawning migrations of anadromous salmon. Recent developments in signal detection based on the Doppler principle, and new information on fish sound scattering characteristics at the high frequencies used in riverine sonar, should result in much improved detection and classification capability. These are discussed along with some practical considerations for the deployment of sonar devices for counting fish in rivers.     

95Zr在海水、底质及海洋生物间的迁移、富集和分布

在模拟海洋环境中,海水中95Zr的比活度在试验前期快速下降,在最初4h内下降了90%以上,此后呈缓慢递减趋势.底质中95Zr的比活度在试验前期逐渐上升,至48h达到最大值,此后随时间逐渐降低.半褶织纹螺螺壳富集95Zr的能力显著强于螺肉,螺壳和螺肉的富集系数分别为10.32和4.68.大弹涂鱼各组织器官中,根据富集量,对95Zr的富集能力最强的是内脏,其次是鳃和鳍,最弱的是肌肉,次弱的是脊椎.大弹涂鱼除鳃外,其余各组织器官的富集系数均小于1.半褶织纹螺对95Zr的富集能力比大弹涂鱼更强.     

Plasma steroid levels in female flounder (Platichthys flesus) after chronic dietary exposure to single polycyclic aromatic hydrocarbons

The chronic effects of polycyclic aromatic hydrocarbons (PAHs) on ovary development, total hepatic lipids and plasma sex- and corticosteroid levels in female flounder (Platichthys flesus) were examined. Sexually mature feral female flounder were exposed via the diet to phenanthrene (0.5, 2.5 or 12.5 nmol/g food) or chrysene (0.4 nmol/g food) for 12 weeks, during the previtellogenic phase of the annual reproductive cycle. PAH exposure did not directly affect germ cell development since no structural and/or developmental differences were observed between control and exposed fish. On the contrary, all treatments resulted in altered plasma steroid levels. The most pronounced effect was the significant decrease in plasma 17 beta-estradiol to 19 +/- 11%, 27 +/- 7%, 63 +/- 20% and 61 +/- 12% in relation to control fish, respectively, in flounders exposed to 12.5, 2.5 or 0.5 nmol phenanthrene/g food and 0.4 nmol chrysene/g food. Impaired ovarian growth was not observed, most likely because experiments were ended before the period of vitellogenesis, even though a non-significant general decline in total hepatic lipids could be observed. Moreover, all exposed flounders, except fish fed with the highest amount of phenanthrene, showed a negative correlation between plasma 17 beta-estradiol and 17 alpha-hydroxyprogesterone levels (r = -0.46). One possible explanation is that PAH action may be mediated by a specific inhibition of steroidogenic enzymes. These findings provide evidence that selected PAHs are antiestrogenic xenobiotics with the capability to impair female teleost reproductive function.     

Microsomal estrogen metabolism in channel catfish

Our goal was to study the involvement of cytochrome P450 genes in estrogen metabolism and the extent to which the potentially carcinogenic 4-hydroxyestradiol metabolite is formed by channel catfish (Ictalurus punctatus; CC). Estradiol metabolism and ethoxyresorufin-O-deethylase (EROD) activity were assessed in several tissues from fish collected from three variably contaminated sites in the Mississippi River Delta, from laboratory control fish, and from fish exposed to 20 mg/kg benzo(a)pyrene (BaP) i.p. for 4 days. Liver EROD activity was induced by BaP, but Delta fish EROD activities were not statistically higher than activities in control fish. Gill microsomal EROD activity was also induced by BaP, but activities were 8- to 77-fold lower than those from liver. The predominant estrogen metabolites formed by CC liver, gill and gonad microsomes were 2-hydroxyestradiol and estrone as detected by GC/MS. Liver and gill 2-hydroxyestradiol formation was induced in BaP-dosed fish. The trends in hydroxyestradiol formation in field collected fish were more variable. In all fish liver microsomes there was more 2- compared to 4-hydroxyestradiol formed. However, BaP-treatment increased the 4:2 hydroxyestradiol ratio from 0.04 in control fish to 0.2 in BaP-exposed fish, suggesting that BaP induces the formation of the potentially genotoxic estrogen metabolite. No detectable 4-hydroxyestradiol was produced by gill and gonad microsomes. These results will ultimately help in determining which fish P450 genes are susceptible to environmental contamination and may be involved in estrogen genotoxicity.     

Seasonal variability of rocky reef fish assemblages: Detecting functional and structural changes due to fishing effects

The present study analyzed the effects of seasonal variation on the stability of fish-based metrics and their capability to detect changes in fish assemblages, which is yet poorly understood despite the general idea that guilds are more resilient to natural variability than species abundances. Three zones subject to different levels of fishing pressure inside the Arrábida Marine Protected Area (MPA) were sampled seasonally. The results showed differences between warm (summer and autumn) and cold (winter and spring) seasons, with the autumn clearly standing out. In general, the values of the metrics density of juveniles, density of invertebrate feeders and density of omnivores increased in warm seasons, which can be attributed to differences in recruitment patterns, spawning migrations and feeding activity among seasons. The density of generalist/opportunistic individuals was sensitive to the effect of fishing, with higher values at zones with the lowest level of protection, while the density of individuals with high commercial value only responded to fishing in the autumn, due to a cumulative result of both juveniles and adults abundances during this season. Overall, this study showed that seasonal variability affects structural and functional features of the fish assemblage and that might influence the detection of changes as a result of anthropogenic pressures. The choice of a specific season, during warm sea conditions after the spawning period (July–October), seems to be more adequate to assess changes on rocky-reef fish assemblages.     

淋巴囊肿病毒mcp基因变异特征及其基因型分析

淋巴囊肿病毒是引起多种海、淡水鱼淋巴囊肿病的病原,且不同淋巴囊肿病毒分离株间存在一定的差异。本文对25株淋巴囊肿病毒分离株mcp基因的变异特征进行分析,结果表明:分离自同一宿主的淋巴囊肿病毒mcp基因序列并非完全一致,有些同宿主分离株间存在着较少的变异,其MCP蛋白序列间的变异位点多位于不规则结构域、属于非蛋白相互作用位点;分属不同基因型淋巴囊肿病毒分离株MCP蛋白序列间的变异位点也多位于不规则结构域,变异位点为蛋白相互作用位点的比率仅占21.98%。金头鲷淋巴囊肿病毒分离株LCDV-sa是一种新的淋巴囊肿病毒基因型,此25株淋巴囊肿病毒可分为7个基因型。对淋巴囊肿病毒变异的研究,可加深对其感染机制的认识,有助于了解其传播途径,可为淋巴囊肿病的防控提供重要的理论依据。