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1.
为了从分子水平研究大菱鲆生长激素作用机制及进化机制.以大菱鲆(Scophthalmus maximus)为材料从脑垂体中提取mRNA,利用SMART-RACE技术建立大菱鲆脑垂体cDNA文库,并从该文库中克隆出大菱鲆生长激素(growth Hormone,GH)cDNA全长序列.测序结果表明,克隆的大菱鲆GH cDNA序列全长为876 bp,包括108 bp的5'UTR和174 bp的3'UTR序列.该基因的开放阅读框全长591 bp,编码由197氨基酸残基组成的生长激素成熟肽序列,用生物软件DNASTAR计算大菱鲆生长激素蛋白分子量为1*!909.22,等电点为6.24.将大菱鲆与漠斑牙鲆、褐牙鲆等共7种鲆鲽鱼类GH成熟肽氨基酸序列进行比较分析,结果显示大菱鲆与其他6种鲆鲽鱼类序列同源性均为70%左右,而鲆科鱼类与鲽科鱼类间生长激素基因同源性很高(≥80%),说明大菱鲆与鲆科、鲽科鱼类的同源性较低.另外,运用PAUP软件对7种鲆蝶科鱼类与另外8种不同种属鱼类进行了分子系统进化树分析,结果与根据传统的形态学和生化特征分类进化地位基本一致,大菱鲆单独形成1个分支且与鲆科和鲽科鱼类相距较远,此结果为在形态学分类基础上进一步定义菱鲆属鱼类分类提供了理论依据.  相似文献   

2.
采用RT-PCR和RACE技术克隆鲫鱼slc7A8基因的全长cDNA序列,对基因序列用生物软件对基因进行生物信息分析,用Real-time PCR方法检测基因在组织中的mRNA表达丰度。结果表明,鲫鱼slc7A8cDNA全长为2709bp,包含195bp的5′UCR序列,921bp的3′UCR序列,1593bp开放阅读框,编码530个氨基酸序列;鲫鱼与斑马鱼基因同源性和编码氨基酸同源性分别为88.9%和95.5%,而与其他动物分别在70.1%-74.8%和80.6%-82.1%之间;预测编码蛋白的分子量为57719.84,等电点为4.8,对其结构预测显示该蛋白具有与哺乳动物十分相似的12个螺旋跨膜结构,跨膜区氨基酸高度保守,不同动物间的同源性都在92.2%以上;Real-time PCR检测鲫鱼组织中的mRNA表达丰度高低顺序为前肠、中肠、脑、后肠、肌肉、肾、鳃、心、肝脏。  相似文献   

3.
利用RT-PCR和RACE方法克隆得到鳜鱼肝脏中控制高不饱和脂肪酸合成的脂肪酸去饱和酶(fatty acid desaturase,FAD)和脂肪酸延长酶(fatty acid elongase,ELO)基因的全长cDNA序列。FAD基因的全长cDNA序列1882bp,编码445个氨基酸,该蛋白序列含有FAD全部的特征结构区,包括3个组氨酸簇、2个跨膜区和1个细胞色素b5结构域,与其它鱼类FAD氨基酸序列的同源性为66.5%-90.1%,系统树分析显示其与欧洲鲈鱼和金头鲷等海水鱼类的亲缘关系最近。获得的ELO基因全长cDNA序列1401bp,编码294个氨基酸,该蛋白序列含有单一的氧化还原中心组氨酸簇、内质网停留信号和多个跨膜区等ELO特征结构,与其它几种鱼类ELO氨基酸序列的同源性为71.8%-86.7%,系统进化分析显示其与南方蓝鳍金枪鱼和金头鲷的亲缘关系较近。鳜鱼FAD和ELO基因全长cDNA序列的获得可为进一步研究其HUFA合成能力及调控机理奠定基础。  相似文献   

4.
利用RT-PCR和快速扩增cDNA末端(rapid amplification of cDNA ends,RACE)技术首次克隆了宽体沙鳅(Botia reevesae)-肌动蛋白基因的cDNA全序列,该序列全长为1795bp,由长100bp的5非翻译区(untranslated region,UTR)、570bp的3非翻译区和1125bp的开放阅读框(open reading frame,ORF)组成,编码375个氨基酸。宽体沙鳅-actin氨基酸序列包含1个糖基化位点、9个N-豆寇酰化位点、3个actin信号位点等主要结构区域。PSI-BLAST比对表明,宽体沙鳅-actin氨基酸与真鲷、罗非鱼、虹鳟等鱼类同源性达99%。NJ法系统进化分析显示宽体沙鳅-actin首先与鲢聚在一起,然后与、尖头等鱼类聚在一起。荧光定量PCR检测-actin基因在宽体沙鳅脑、鳃、心脏、肝、胃等12个组织的表达无显著差异(P<0.05),具有良好的稳定性。  相似文献   

5.
根据已报道的铁结合蛋白基因的保守序列设计引物,用cDNA末端快速扩增(RACE)法,成功地从可口革囊星虫体液中获得铁结合蛋白基因的全长序列.结果表明,该基因cDNA全长1017bp,5'-端非编码区为15lbp,3'一非编码区为341bp,开放阅读框长度为525bp(括一个终止密码子),可编码175个氨基酸(GenBank:EU091352).该序列与加洲海兔、皱纹盘鲍、刺参、微小牛蜱、叉尾鲴、非洲爪蟾、小家鼠、人等的铁结合蛋白基因有67%-75%的同源性,而相应的氨基酸同源性为59%-76%.氨基酸相似性为74%*-89%%.分析结果表明,铁结合蛋白基因在动物进化中是高度保守的.  相似文献   

6.
根据其他鱼类DMRT1基因中的保守序列设计了一对简并引物 ,利用反转录 多聚酶链式反应 (RT PCR)的方法克隆了黑鲷 (Acanthopagrusschlegeli)DMRT1基因cDNA的一个片段 .该片段长 13 8bp ,推导的氨基酸序列由 45个氨基酸残基组成 .同源性分析表明 ,该cDNA片段与其他鱼类DMRT1基因序列具有较高的同源性  相似文献   

7.
采用同源克隆的方法、利用RACE技术从黄鳍金枪鱼(Thunnus albacares)肝脏中克隆了其MIF(TaMIF)的cDNA序列.TaMIF的cDNA全长706 bp含一个345 bp的开放阅读框,编码一个长115氨基酸的蛋白质.信号肽预测分析表明TaMIF没有信号肽.序列分析与进化分析表明,黄鳍金枪鱼与近海养殖鱼类MIF的氨基酸序列高度相似、进化地位相近,预示着深海鱼类TaMIF与近海养殖鱼类具有相似的生物学功能.研究结果是对深海鱼类MIF基因信息资料的重要补充.  相似文献   

8.
利用已报道的FeSOD保守区域,设计简并引物,通过简并PCR的方法获得了雨生红球藻(Haematococcus pluvialis)FeSOD(HpFeSOD)cDNA的部分序列,然后采用RACE方法分别克隆到5′端和3′端。拼接后得到HpFeSOD cDNA全长,该基因全长为1 138 bp,ORF为684 bp,编码227个氨基酸。把已经得到的HpFeSOD序列推导成氨基酸序列与一些已知物种的FeSOD氨基酸序列相比较,雨生红球藻FeSOD与杜氏藻、衣藻、团藻、石莼、颤藻的同源性为89%、83%、78%、70%和63%。分子系统学分析表明,雨生红球藻FeSOD与杜氏藻FeSOD聚在一起,介于真菌与高等植物之间并且真核微藻FeSOD与高等植物的同源性更高,推测其在进化上与高等植物的亲源关系更近。  相似文献   

9.
采用RT-PCR及RACE法从斜带石斑鱼Epinephelus coioides肝胰脏克隆得到胰蛋白酶原(trypsinogen,TRY)与淀粉酶(amylase,AMY)基因cDNA全序列.斜带石斑鱼肝胰脏TRY基因cDNA全长911 bp,其中5非翻译区(5'-UTR)为55bp,3'-UTR为127bp,开放阅读框(ORF)为729bp,编码242个氨基酸,包含所有丝氨酸蛋白酶中共有的高度保守的催化活性中心.序列一致性分析发现,斜带石斑鱼与牙鲆Paralichthys olivaceus、金头鲷Sparus aurata、鳎Solea senegalensis、石鲽Pleuronectes bicoloratus的TRY序列相似性高达86.8%-89.70%,与人Homo sapiens小鼠Mus musculus、斑马鱼Danio rerio的TRY相似性较低为59.9%-64.5%.斜带石斑鱼AMY基因cDNA全长1657bp,其中5'-UTR为41bp,3'-UTR为77 bp,ORF为1539bp,编码512个氨基酸,包含与哺乳动物α-AMY二级结构相似的8个α旋和8个β折叠.序列一致性分析发现,斜带石斑鱼与澳洲肺鱼Neoceratodus forsteri、美洲拟鲽Limanda americanus、大西洋鲑Salmo salar、斑马鱼AMY基因序列相似性高达82.4%-91.8%,与人、小鼠、鸡G.Gallus的AMY基因相似性较低为70.1%-72.3%.斜带石斑鱼TRY和AMY基因cDNA全序列的成功克隆为进一步研究其表达调控机理及研发有效提高其表达水平的饲料添加剂奠定基础.  相似文献   

10.
小球藻△12脂肪酸去饱和酶基因的克隆与序列分析   总被引:1,自引:0,他引:1       下载免费PDF全文
利用已报道的△12脂肪酸去饱和酶基因序列的保守区域,设计简并引物,通过RT-PCR的方法获得了小球藻NJ-7的内质网型△12脂肪酸去饱和酶基因(CvFAD2)的部分序列,然后采用RACE的方法分别克隆到5'片段和3'片段,拼接后设计特异引物扩增到全长cDNA.该基因全长为2 032 bp,ORF为1158 bp,编码385个氨基酸,分子质量约为44 ku.根据已经得到的CvFAD2序列推导成氨基酸序列与一些已知物种的FAD2氨基酸序列相比较,同源性分别为普通小球藻(Chlorella vulgaris)75%,莱菌衣藻(Chlamydomonas reinhardtii)57%,石榴(Punica granatum)57%,麻疯树(Jatropha curcas)52%.系统发育分析表明,南极小球藻CvFAD2基因与真核微藻(衣藻和普通小球藻)的FAD2基因聚在一起,介于真菌与高等植物之间,并且真核微藻FAD2基因与高等植物的同源性更高,推测其在进化上与高等植物的亲源关系更近.  相似文献   

11.
12.
The potential of the first line of the active oxygen-scavenging system, partial cDNA encoding Cu/Zn superoxide dismutase (SOD) was isolated in three aquatic mollusc species: Ruditapes decussatus (marine clam), Dreissena polymorpha (continental water mussel) and Bathymodiolus azoricus (hydrothermal vent mussel). These SOD cDNA fragments were amplified by PCR with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the Cu/Zn-SOD from several other organisms. A partial cDNA of CuZn-SOD was obtained for R. decussates (510 bp), D. polymorpha (510 bp) and B. azoricus (195 bp). The deduced amino acid sequence showed high similarity among the three mollusc species (57-63%) and among other species (50-65%). The residues involved in coordinating copper (His-47, 49, 64, 121) and zinc (His-64, 72, 81 and Asp-84) were well conserved among the three Cu/Zn-SOD sequences.  相似文献   

13.
1 Introduction T he translationally controlled tum or protein(TC TP) w as firstdescribed as a grow th-related proteinin m ouse E hrilisch ascites tum or cells and ery-throleukem ia cells (Y enofsky etal., 1983). Subse-quently, TC TP w as founded to be present in m anycells (Sanchez etal., 1997; G ross etal., 1989; C hunget al., 2000; V ercoutter-Edouart et al., 2001) exceptthe hum an kidney cell(Sanchez etal.,1997;G achetetal., 1999). H om ologues of TC TP have been reportedfrom sever…  相似文献   

14.
胰岛素样生长因子-I(Insulin-like growth factor-I,IGF-I)是影响脊椎动物生长、发育及代谢的重要调控因子。本研究采用RT-PCR和RACE技术,克隆了银鲳(Pampus argenteus)肝脏IGF-IcDNA序列,应用半定量RT-PCR、Real-time q PCR和原位杂交的方法检测了IGF-I的组织表达特性、在肝脏中的生长表达特性和IGF-I基因在肝脏中的定位。序列分析表明,IGF-I cDNA序列全长836bp,其5′非编码区128bp、3′非编码区92bp,开放阅读框(open reading frame,ORF)605bp,由此推导IGF-I前体蛋白由201个氨基酸组成;前体肽由信号肽、成熟肽、E肽三部分组成,其中信号肽59个氨基酸,成熟肽68个氨基酸,E肽74个氨基酸;成熟肽由B、C、A、D四个区域组成,E肽分析表明,银鲳IGF-I属Ea-4型。同源性比较结果表明,银鲳与同目鲈形目鱼类的IGF-I编码序列同源性较高,为83.52%—91.40%;与哺乳类、鸟类和爬行类的同源性较低。半定量RT-PCR和Real-time q PCR组织特异性表达结果显示,IGF-I m RNA在肝脏组织中的表达量最高,显著高于其它组织,肾脏、心脏、肌肉、脑、鳃、小肠、卵巢次之,嗅球、脾脏和胃中表达较低;半定量RT-PCR和Real-time q PCR不同生长阶段表达结果显示,IGF-I m RNA在30—50g肝脏组织中表达量最高(P0.05);IGF-I m RNA在肝脏中的原位杂交定位结果显示,在肝脏细胞中均有表达,阳性信号主要位于细胞质中,靠近细胞边缘处信号较强。  相似文献   

15.
瘦素(Leptin)是在动物摄食和能量代谢调节中具有重要作用的一种蛋白。为研究光唇鱼(Acrossocheilus fasciatus)中Leptin基因(AfLep)的结构和功能,作者克隆了其c DNA序列全长。结果显示AfLep由1315个核苷酸组成,含1个长度为516bp的开放阅读框,预测编码蛋白由171个氨基酸残基组成并具有长度为20aa的信号肽。系统进化树中AfLep与其他鲤科鱼类的Leptin蛋白聚为一簇,与齐口裂腹鱼(Schizothorax prenanti)进化相关性最高。多重序列比对显示AfLep与齐口裂腹鱼Leptin蛋白相似性最高(86.7%),与鲤科其他鱼类间的相似性均在80%以上。AfLep具有脊椎动物Leptin蛋白的4个保守?螺旋结构,其三级结构与人Leptin相似。AfLep在光唇鱼肝脏中的表达量最高,其次是脑和肾,其他组织中仅有微弱表达。实时荧光定量PCR检测显示禁食后光唇鱼肝脏AfLep表达量降低(P0.05),禁食1d、3d、7d时的表达量分别比与禁食前降低了58.25%、73.82%和92.05%;禁食1d和3d的鱼经再投喂后肝脏AfLep表达量均显著升高(P0.05),但禁食7d的鱼再投喂后AfLep表达量仅略有升高(P0.05)。上述结果表明AfLep参与了光唇鱼的摄食管理和能量代谢调控。  相似文献   

16.
The toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and its related planar halogenated aromatic hydrocarbons (PHAHs) are mediated by the aryl hydrocarbon receptor (AHR). To investigate the potential sensitivity to PHAHs and the evolutional diversity of AHR in aquatic birds, AHR cDNAs were initially cloned and sequenced from the livers of a black-footed albatross (Diomedea nigripes) and a common cormorant (Phalacrocorax carbo). In this study, we report the identification of two distinct AHR paralog genes in these species. The two full-length AHR cDNAs from albatross were highly divergent (33% overall amino acid identity, and 60% identity in the N-terminal half). Phylogenetic analysis showed that one of them belongs to the AHR1 clade and the other one to the AHR2 clade, which has been identified only from fishes, but not yet from mammals and birds. Albatross AHR1 encoded a 861-residue protein with a predicted molecular mass of 96.7 kDa, and in the case of albatross AHR2, 925 amino acids and 100.7 kDa. From cormorant liver, the full-length AHR1 cDNA and the partial AHR2 cDNA were cloned. This result strongly suggests that bird species also possess two distinct AHR genes (AHR1 and AHR2). To our knowledge, this is the first report on the presence of an AHR2-like isoform in bird species as well as in fish.  相似文献   

17.
Paralytic shellfish poisoning (PSP) toxins have been implicated as the causative agent of a number of fish kills. Exposure experiments indicate that fish are susceptible to PSPs by intraperitoneal (i.p.) and oral administration, while sampling of fish affected by toxic blooms reveals that these toxins can be accumulated. In spite of the potential impact to marine fisheries, little research has been conducted on the potential metabolism and detoxification of PSPs in marine fishes. Previous work by this group has shown that the xenobiotic metabolising enzyme (XME) cytochrome P-450 (CYP1A) is induced in Atlantic salmon (Salmo salar) following i.p. exposure to saxitoxin (STX). Salmon injected i.p. with sub-lethal doses of STX show a four- to eight-fold induction of hepatic CYP1A (as shown by ethoxyresorufin-O-deethylase activity) over controls after 96 h. Results presented here show that the phase II XME glutathione S-transferase (GST) is also induced in salmon following PSP exposure. Post smolts were exposed to three injections of PSPs (2 micrograms STXeq/kg) over 21 days. Injection of both STX and PSPs extracted from a toxic strain of dinoflagellate (Alexandrium fundyense, CCMP 1719) resulted in induction of hepatic GST, as measured by activity for 1-chloro 2,4-dinitrobenzene. Such inductions indicate a potential role for XMEs in PSP metabolism. Possible roles for other enzymes are also discussed.  相似文献   

18.
克隆获得缢蛏(Sinonovacula constricta)谷胱甘肽S-转移酶(Sc-GSTσ)和热休克蛋白90(Sc-HSP90)基因的cDNA全长,分析了它们的组织表达差异及其在氨氮胁迫下的表达特征。结果表明,Sc-GSTσ的全长cDNA为1 414 bp,含有639 bp的开放阅读框(Open Reading Frame,ORF),编码212个氨基酸,Sc-GSTσ氨基酸序列与其他物种的GST氨基酸序列同源性为31.88%~43.40%;而Sc-HSP90的全长cDNA为2 752 bp,ORF为2 181 bp,编码726个氨基酸,其氨基酸序列与其他物种HSP90的氨基酸序列同源性为76.77%~87.05%。荧光定量PCR分析发现,Sc-GSTσ和Sc-HSP90在缢蛏各组织中均有表达,两者均在肝胰腺中表达量最高。氨氮胁迫后,Sc-GSTσ和Sc-HSP90 mRNA在肝胰腺中表达均显著上调(p<0.05),表明氨氮胁迫引起机体的应激反应,2个基因可能参与机体解毒或防御过程。但胁迫后期表达量下降推测是机体的防御能力有限,不足以完全保护宿主免受应激诱导的细胞损伤。  相似文献   

19.
Multixenobiotic resistance mechanism (MXR) in aquatic organisms is mediated by the activity of the P-glycoprotein (Pgp) transporter that binds and actively effluxes different chemicals out of cell. In addition to the Pgp, several other, non-Pgp transport proteins have been recently identified in different human and animal tissues. Given their characteristics and tissue distribution we hypothesized that members of the so-called multidrug resistance-associated protein (MRP) family may be expressed in aquatic organisms. This study attempted to identify MRP related genes in different tissues of several marine and freshwater bivalves (Mytilus galloprovincialis, Dreissena polymorpha, Anodonta cygnea) and fish species (Mullus barbatus, Cyprinus carpio, Salmo trutta). Following an alignment of known MRP1 and MRP2 human sequences, as well as the GenBank available mrp2 sequences from different animals, we determined highly conserved regions and used them to design three pairs of consensus primers. Total RNA was isolated, reverse transcribed to cDNA and the obtained cDNAs were PCR amplified with the corresponding primers. The amplified PCR products were sequenced and their homology compared with Pgp and MRP protein sequences from different species. The expression of MRP related mRNA was clearly identified only in liver tissue isolated from red mullet, with homologies at the protein level ranging from 75% to 76%. Described results clearly pointed at the possibility that at least in the red mullet MXR as a general defense mechanism may be mediated by the activities of at least two different types of transport proteins.  相似文献   

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