苯并(a)芘和芘对梭鱼肝脏DNA损伤的研究

用苯并(a)芘、芘以及它们的等量混和物,分别在浓度为0.1,1,10,20,50μg/dm3浓度下对梭鱼暴污,5d后取梭鱼肝脏和鳃用碱解旋法分别测定其DNA的损伤,结果随着污染物浓度的增加,肝脏DNA损伤程度增加;在相同浓度下,苯并(a)芘和芘的联合毒性大于苯并(a)芘和芘分别作用时的毒性之和。所以苯并(a)芘和芘对DNA损伤的联合作用应为加强作用。     

中国海盘海牛科(腹足纲, 裸鳃目)一新记录属和一新记录种

2021年3月在大连进行潮间带生物调查时采集到2个裸鳃类标本,经鉴定发现为欧氏针盘海牛Diaulula odonoghuei (Steinberg, 1963),为中国新记录属和新记录种。在研究中对其进行了活体拍照,利用光学显微镜和扫描电子显微镜对其外部形态和内部解剖特征进行了观察。此外,测定了这两个标本的COI、16S rRNA和H3基因序列,将测得的基因片段与GenBank数据库中的针盘海牛属Diaulula的同源序列进行对比分析,构建了针盘海牛属的系统发育树。欧氏针盘海牛在我国沿海的发现,进一步丰富了中国海软体动物的物种多样性研究。     

Differentiation of coral trout (Plectropomus leopardus) based on an analysis of morphology and complete mitochondrial DNA: Are cryptic species present?

Two morphotypes of Plectropomus leopardus have been identified; morphometric and meristic analyses show that there is no diagnostic difference between them. A difference in color pattern was the most appropriate phenotypic character with which to distinguish between the two morphotypes. Complete mitochondrial DNA sequencing, however, indicated a clear difference between the two morphotypes. Barcoding analysis revealed no significant difference (P>0.05) in CO1 or ND2 divergence among intramorphotypic individuals, even between geographically separated populations, whereas the intermorphotypic CO1 and ND2 divergences were large enough (averaging 0.95% for CO1 and 1.37% for ND2) to clearly discriminate between the two morphotypes. The color pattern difference, geographical distribution, together with the mtDNA and barcode sequencing data, suggest that the two morphotypes should be of two subspecies or even two species.     

条斑紫菜SSU 中内含子分析

根据GenBank中已知的条斑紫菜(Porphyra yezoensis)SSU和LSU r RNA基因序列分别设计引物,分别以混合个体和单个个体的基因组DNA以及c DNA为模板进行扩增,测序分析后推测SSU r RNA基因中的内含子转录后加工可能仍被保留,而在LSU r RNA基因上游序列中没有发现内含子。长511bp的内含子位于SSU r RNA基因序列的上游,其插入位点为TCTGGTG-CCAGCAGCC,内含子5′和3′端的核苷酸序列分别为AAC-和-ATGG。该内含子的剪接位点以及保守区P,Q,R,S与I型内含子是不同的。研究发现,在同种紫菜中,不同个体SSU基因中内含子的有无、分布及结构特征是不同的,说明内含子对于分类是不太适合的。但是内含子的长度以及核苷酸序列在种间又具有一定的特异性,可以为红藻种间以及种内亲缘关系较远的亚种和不同地理群的区分和鉴定提供参考。     

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。     

DNA tracers with information capacity and high detection sensitivity tested in groundwater studies

 In order to investigate the usefulness of unique synthetic DNA tracers in groundwater, a field experiment was conducted in Norway. DNA tracers and a sodium-chloride tracer were injected into an aquifer. The transport of DNA molecules was interpreted by comparing with the plume of chloride ions under forced-gradient steady-state flow conditions. Spatial concentration moments described the migration of conservative tracers. Mobility and migration of DNA in groundwater demonstrate that DNA tracers can be detected by using the polymerase chain reaction (PCR) and DNA sequence analysis. The results indicate that DNA tracers can be valuable tools as tracers in groundwater investigations. Received, June 1997 / Revised, July 1998, December 1998 / Accepted, January 1999     

两种体色三疣梭子蟹线粒体DNA 部分片段序列的比较分析

三疣梭子蟹(Portunus trituberculatus)作为重要的海洋经济动物,其常见体色(头胸甲)为茶绿色。近年来在我国沿海海域海捕三疣梭子蟹中开始出现体色为紫色的一类梭子蟹,除体色不同外,二者表型特征并无显著差异。对两种体色三疣梭子蟹不同个体的线粒体COI和16S rRNA基因进行了序列比对分析以判定二者之间的亲缘关系。结果发现COI和16S rRNA基因在两种体色三疣梭子蟹群体中的核苷酸序列一致性分别为99.87%和99.88%,表明紫色三疣梭子蟹并未发生亚种的分化,即紫色和茶绿色群体属于同一个种。并利用GenBank数据库检索了梭子蟹科其他15种海产蟹的16S rRNA序列,进行了序列同源性比对分析和分子系统学方面的探讨,为梭子蟹种属分类学研究提供分子依据。     

Relationships between molecular bacterial diversity and chemistry of groundwater in the Wairarapa Valley,New Zealand

Groundwater plays an important role in New Zealand water supplies and hence monitoring activities are conducted regularly. Most monitoring programmes aim to evaluate groundwater chemistry and almost completely overlook the microbial component in this ecosystem. In our present study, the bacterial community structure of groundwater in the Wairarapa Valley was examined using the terminal restriction fragment length polymorphism (T-RFLP), and relationships between bacterial community structure and groundwater chemistry, aquifer confinement and groundwater usage were explored. In addition, the results from this study were compared with a previous T-RFLP survey of the same area in an attempt to detect changes in bacterial community structure over time. The data obtained suggested that bacterial community structure was related to groundwater chemistry, especially to redox conditions. Species composition showed minimal variation over time if groundwater chemistry remained unchanged. These findings reflect the potential of using bacterial communities as biological indicators to evaluate the health of groundwater ecosystems. We suggest that it is important to include this type of broad bacterial diversity assessment criteria into regular groundwater monitoring activities.     

基于微卫星标记的三疣梭子蟹家系系谱认证

用6个微卫星标记对三疣梭子蟹(Portunus trituberculatus)的6个家系进行系谱鉴别和遗传多样性研究。6个微卫星标记在6个家系中显示了高度的遗传差异,6个位点的多态信息含量(PIC)分别为Pot09位点0.6045,Pot14位点0.6072,Pot17位点0.8130,Pot18位点0.6870,Pot25位点0.7839,Pot42位点0.6330。6个多态性位点共发现了32个等位基因,每个位点的等位基因数在4～8个之间。不同位点共发现7个家系特异性等位基因,2#和3#家系中各发现2个,1#、5#、6#家系中各发现1个,4#家系未发现特异性等位基因。根据已知亲本及子代基因型,可推断出6个家系中全部亲本的基因型,据此鉴别各家系。在Pot18位点可将1#家系和6#家系与其他家系相区别;Pot14位点和Pot17位点可将3#家系与其他家系相区别;Pot42位点可将5#与其他家系相区别;Pot17位点和Pot25可将2#家系与其他家系相区别。因此,Pot18位点、Pot14位点和Pot17位点、Pot42位点、Pot17位点和Pot25位点可分别用于鉴别1#和6#家系、3#、5#、2#家系的特异性标记。研究表明,在选用的6个微卫星标记中,最少选用3个标记可鉴别6个三疣梭子蟹家系。     

DNA identification of Pacific bluefin tuna (Thunnus orientalis) in the New Zealand fishery

Muscle samples were collected from 69 specimens identified as Pacific bluefin tuna (Thunnus orientalis) (Temminck and Schlegel, 1844) in the New Zealand Exclusive Economic Zone (EEZ) between 1990 and 2000. Identifications before 1996 were based on body size and colour of the caudal keel; later identifications were mostly based on the shape of abdominal cavity. The tissue samples were tested with a diagnostic mitochondrial DNA marker that distinguishes southern bluefin Thunnus maccoyii (Castelnau, 1872) and Pacific bluefin tuna T. orientalis; 59 specimens were confirmed as T. orientalis and 10 as T. maccoyii. Specimens recorded as Pacific bluefin tuna by the shape of the abdominal cavity were correctly identified as T. orientalis, and this character can be used to identify large specimens landed on tuna vessels. Some specimens recorded as Pacific bluefin tuna on the basis of colour and size were T. maccoyii; and early records of T. orientalis in New Zealand waters, based on these characters, are unreliable. Unusual colour patterns were reported in some specimens of T. orientalis but not T. maccoyii. The Pacific bluefin tuna T. orientalis accounted for less than 0.3% of the bluefin tuna catch in the New Zealand EEZ during the 1990s.