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61.
Macroalgal surfaces are prone to being attached by bacteria. Epibacterial community structures on marine macroalgae are host-specific but temporally and spatially variable. In this study, we investigated the structure of epibacterial communities on the surfaces of four red macroalgae, Gracilaria lemaneiformis, Gloiopeltis furcata, Mazzaella sp. and Porphyra yezoensis, by analyzing the sequences of 16 S r RNA gene libraries. Healthy individuals of all macroalgae species were collected in winter from a farm at Dalian, China. The results showed that the epibacterial communities were mainly dominated by α-Proteobacteria, γ-Proteobacteria and Bacteroidetes. Deinococcus-Thermus, Spirochaetes and ε-Proteobacteria were also found. The majority of cloned sequences shared the greatest similarity to those of culturable organisms. A large portion of sequences from the α-Proteobacteria homed in Roseobacter clade, i.e., genera Ahrensia, Roseovarius, Litoreibacter, Octadecabacter, Thaiassobacter and Sulfitobacter, while members of Bacteroidetes mainly belonged to family Flavobacteriaceae. The cloned sequences could be separated into 66 OTUs at 0.01 distance value, and rare common OTUs were found among libraries. At genus level, Pseudoalteromonas dominated Gr. lemaneiformis and Gl. furcata libraries, accounting for 72.2% and 47.3%, respectively. Sulfitobacter dominated P. yezoensis library, accounting for 35.4%. A previously undefined cluster within Deinococcus-Thermus dominated Mazzaella sp. library, accounting for 24.6% of the all. These results indicated that a broad range of bacteria inhabited the surfaces of these macroalgae.  相似文献   
62.
Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene (COI) was used to identifing five sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.  相似文献   
63.
三疣梭子蟹HMGR基因的克隆及其在蜕皮中的表达分析   总被引:2,自引:1,他引:1  
为了研究3-羟基-3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methyl glutaryl coenzyme A reductase,HMGR)在甲壳动物蜕皮调控中的作用,采用RT-PCR和c DNA末端快速扩增技术(RACE),克隆得到三疣梭子蟹(Portunus trituberculatus)HMGR基因的c DNA序列(Gen Bank登录号:KF280756)。该序列全长2575bp,包括一个53bp的5′端非编码区,一个686bp的3′端非编码区和一个长度为1836bp的开放阅读框,编码611个氨基酸。该氨基酸序列与已公布的美洲海鳌虾HMGR氨基酸序列相比一致性达65%,具有Ⅰ型HMGR保守催化区域、两个HMG-Co A结合基序和两个NADP(H)结合基序。采用实时荧光定量PCR(q RT-PCR)技术,分析三疣梭子蟹HMGR基因的组织差异表达及在蜕皮周期中的表达水平变化,结果表明HMGR基因在三疣梭子蟹大颚器(MO)中的表达量最高,在其它组织中表达量均极低;在三疣梭子蟹蜕皮周期中,大颚器中HMGR基因的表达量自A期至D0亚期升至最高,然后下降,至D4亚期最低。验证了大颚器是三疣梭子蟹合成甲基法尼酯的唯一器官,表明HMGR在三疣梭子蟹蜕皮调控中起着重要作用。  相似文献   
64.
王渝  吕建建  刘萍  高保全  李健  陈萍 《海洋与湖沼》2014,45(6):1359-1366
本研究克隆了三疣梭子蟹(Portunus trituberculatus)胞内氯离子通道蛋白基因,命名为Pt CLIC。该基因c DNA全长2000bp,5’和3’非编码区(UTR)长分别为76bp和1162bp,开放阅读框长762bp,推测编码253个氨基酸,预测分子量为29.2k Da,理论等电点为5.93。生物信息学分析表明,Pt CLIC基因中未发现跨膜结构域,属于不稳定蛋白;同源性分析表明,Pt CLIC基因编码的氨基酸序列与蚤状溞(Daphnia pulex)CLIC基因的同源性高达83%;系统进化分析表明,三疣梭子蟹与拟穴青蟹首先聚为一支;实时荧光定量RT-PCR分析表明,Pt CLIC基因在选取的所有组织中均有表达,在肝胰腺中的相对表达量最高,且显著高于其它组织(P0.05)。低盐度胁迫显著改变了Pt CLIC基因在三疣梭子蟹鳃和肝胰腺中的表达模式,整体呈先上调后下调的趋势,并发现该基因在低盐耐受和低盐敏感家系中的表达规律差异显著。研究结果表明Pt CLIC基因在三疣梭子蟹渗透压调节中发挥重要作用,可辅助三疣梭子蟹耐低盐品系的选育。  相似文献   
65.
通过RT-PCR及Smart?TM Race技术,首次克隆了三疣梭子蟹(Portunus trituberculatus)CYP2基因cDNA全长序列。该基因cDNA全长1662bp,编码一个由492个氨基酸组成的多肽,预测理论等电点为6.348,分子量大小为56.68kD。氨基酸序列中含有CYP基因家族所特有的K螺旋保守序列(ExxR)和血红素结合区(FxxGxxxCxG)。经氨基酸序列比对及系统进化树分析发现,与岸蟹(Carcinus maenas)的同源性最高,达到75%。实时荧光定量PCR结果表明,CYP2基因在肝胰腺、鳃、肌肉、血淋巴、心脏和眼柄中均有分布,在肝胰腺中表达量最高。肌肉注射磺胺嘧啶后,三疣梭子蟹高、中、低三剂量组CYP2基因表达较对照组都有上调,并具有时间差异性,低剂量组表达量逐渐降低,趋于对照组,中剂量组和高剂量组表达量先升高后降低,6h后同一时间点,均是高剂量组表达最高,低剂量组最低。表明磺胺嘧啶可诱导三疣梭子蟹CYP2基因,CYP2基因可能参与三疣梭子蟹的药物代谢反应。  相似文献   
66.
鳗鲡目鱼类线粒体基因组的基因组成较为保守,在58个线粒体基因组中,仅有3个物种存在基因数量的差异。在19个鳗鲡目鱼类线粒体基因组中存在主编码基因的重排。主编码基因的变异位点分析结果支持nad5、nad4和nad2基因作为cox1和lrRNA基因辅助的分子标记。鳗鲡科Anguillidae的20个种(亚种)聚在一起,强烈支持鳗鲡科为单系群(BPP=100)。鳗鲡科下属的3个类群(大洋洲类群、大西洋类群和印度洋-太平洋类群)也同时得到有力的验证(BPP均为100)。线鳗科Nemichthyidae和锯齿鳗科Serrivomeridae亲缘关系最近,二者聚类后,与鳗鲡科Anguillidae构成姊妹群(BPP=100)。在囊喉鱼亚目Saccopharyngoidei中,宽咽鱼科Eurypharyngidae与囊鳃鳗科Saccopharyngidae聚类(BPP=100),同时,单颌鳗科Monognathidae与月尾鳗科Cyematidae聚类(BPP=100),4个科聚在一支,支持囊喉鱼亚目为单系群(BPP=100)。在囊喉鱼亚目线粒体基因组中,3个物种(吞鳗Eurypharynx pelecanoides、拉文囊鳃鳗Saccopharynx lavenbergi和杰氏单颌鳗Monognathus jesperseni)存在主编码基因的重排。16种鳗鲡(细美体鳗Ariosoma shiroanago、短吻颈鳗Derichthys serpentinus、凯氏短尾康吉鳗Coloconger cadenati、鸭颈鳗Nessorhamphus ingolfianus、龟草鳗Thalassenchelys sp.、粗犁齿海鳗Cynoponticus ferox、百吉海鳗Muraenesox bagio、巨斑花蛇鳗Myrichthys maculosus、大吻沙蛇鳗Ophisurus macrorhynchos、几内亚副康吉鳗Paraconger notialis、哈氏异康吉鳗Heteroconger hassi、小头鸭嘴鳗Nettastoma parviceps、弱头鳗Leptocephalus sp.、斑点长犁齿鳗Hoplunnis punctata、尖吻小鸭嘴鳗Facciolella oxyrhyncha和星康吉鳗Conger myriaster),与鳗鲡目线粒体主编码基因的原始排列相比,共享nad6基因的易位。同时,基于线粒体基因组13个蛋白质编码基因构建的系统演化树,强烈支持这16个物种聚为一支(BPP=100)。然而,由此而带来的海鳗科Muraenesocidae、拟鯙科Chlopsidae和糯鳗科Congridae是否为单系群的问题,值得今后深入探究。  相似文献   
67.
A sediment sample was collected from a deep-sea hydrothermal vent field located at a depth of 2 951 m on the Southwest Indian Ridge. Phylogenetic analyses were performed on the prokaryotic community using polymerase chain reaction(PCR) amplification of the 16 S rRNA and nifH genes. Within the Archaea, the dominant clones were from marine benthic group E(MBGE) and marine group I(MGI) belonging to the phyla Euryarchaeota and Thaumarchaeota, respectively. More than half of the bacterial clones belonged to the Proteobacteria, and most fell within the Gammaproteobacteria. No epsilonproteobacterial sequence was observed. Additional phyla were detected including the Actinobacteria, Bacteroidetes, Planctomycetes, Acidobacteria, Nitrospirae, Chloroflexi, Chlorobi, Chlamydiae, Verrucomicrobia, and candidate divisions OD1, OP11, WS3 and TM6, confirming their existence in hydrothermal vent environments. The detection of nifH gene suggests that biological nitrogen fixation may occur in the hydrothermal vent field of the Southwest Indian Ridge. Phylogenetic analysis indicated that only Clusters I and III NifH were present. This is consistent with the phylogenetic analysis of the microbial 16 S rRNA genes, indicating that Bacteria play the main role in nitrogen fixation in this hydrothermal vent environment.  相似文献   
68.
Fructose-1,6-bisphosphatase(FBPase) is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends(RACE) technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region(UTR) of 92 bp, a 3′?UTR of 69 bp, and an open reading frame(ORF) of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.  相似文献   
69.
正1 Introduction Dunaliella Salina,which taxi Dunaliella,Volvocales,Chlorophyceae Chlorophyta,is unicell algae with double flagllum at top,and cup shaped chloroplast without cell wall.Dunaliella Salina is the most salt tolerance eucaryotes.It can grow at the range of salt concentration  相似文献   
70.
主要对以色列野生二粒小麦赫尔蒙种群中分离获得的一个抗条锈病基因进行了分子定位研究 ,将源于赫尔蒙山具抗杀锈病的种系 T.dicoccides H52与普通的栽培种 Langdon进行杂交并创建了 F2 代遗传图。研究发现 H52种系抗条锈病的能力由一种显性基因控制 ,将其暂定名为 Yr H52。从 1 2 0个微卫星标记中 ,已经检测到来自亲本 91 %的多态性 ,而且从其中 56个微卫星分子标记中产生了 79个分离的位点 ,有 9个位点显示出了与 Yr H 52基因连锁 ,其重组率 0 .0 2~ 0 .3 5,遗传距离 2 .0 0~ 4 3 .3 7cm之间 ,L OD值 3 .56~ 54.2 2。由 1 0个微卫星位点和 Yr H52构建的染色体 1 B遗传图 ,其图距全长为 1 0 1 .5cm。Yr H52基因位于 Xgwm2 64 a和 Xgwm2 64 c之间 ,且与 Xgwm2 64 a、Xgwm1 8紧密连锁 ,两侧依次分别与 Xgwm1 3 1 a、Xgwm63 6b、Xgwm2 64 c、Xgwm4 0 3 a、Xgwm1 53、Xgwm550 a和 Xgwm1 2 4连锁。同时 ,Yr H52也与 REL P标记物 N or1紧密连锁 ,图距 1 .4 cm,L OD2 9.62。这显然与野生二粒小麦另一个抗条锈病基因 Yr1 5不同 ,研究证明 Yr1 5与 N or1图距是 1 1 .0 cm。  相似文献   
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