玉米亚硫酸氧化酶基因的克隆及其结构与表达分析

为明确亚硫酸氧化酶(sulfite oxidase,SO)基因的结构特征和进化关系及其在玉米不同组织器官发育过程中的表达和分布特性,采用RACE技术克隆了玉米SO基因(ZmSO)的全长cDNA。序列分析表明,获得的ZmSO全长1 492bp,其中5′-UTR 160bp,3′-UTR 138bp,开放阅读框为1 194bp,编码397个氨基酸组成的蛋白质。对该基因编码氨基酸保守结构域的分析发现,ZmSO包含1个钼辅因子结合域、1个自身二聚化域和1个过氧化物体靶信号序列。系统进化分析显示,SO在进化上较为保守,玉米与其它植物的SO相似性较高。荧光定量RT-PCR分析表明,在玉米成株期,根、茎、叶、雄花和幼穗中,ZmSO在根部表达丰度最低,在叶片和幼穗中表达量较高。酶活性测定结果显示,不同器官中SO活性与其mRNA转录水平上的表达趋势相似。     

雌核发育二倍体鲫鲤Dmc1基因的全长cDNA克隆及表达分析

Dmc1（disrupted meiotic cDNA）基因是一个在减数分裂前期Ⅰ表达的特异基因,其产物是减数分裂前期Ⅰ同源染色体配对所必需的。根据据酵母菌、小鼠以及人的DMC1中保守的氨基酸基序设计简并引物,PCR扩增克隆获得了第四代雌核发育二倍体鲫鲤（G4）Dmc1基因部分cDNA序列。在此基础上,通过RACE获得了G4Dmc1基因全长cDNA序列,长度为1369bp,其中开放阅读框为1029bp,编码含342个氨基酸的蛋白质。同时,系统进化分析表明,在进化过程中Dmc1基因在鱼类中保持着高度保守的进化特征。RT-PCR结果表明,Dmc1基因只在G4性腺中表达,在其他组织中不表达。通过实时荧光定量PCR,对Dmc1基因在G4和普通鲤鱼的早期卵巢的表达进行分析,发现G4表达比鲤鱼高。由此可见,雌核发育二倍体鲫鲤Dmc1基因也是减数分裂特异基因,而且其高表达暗示雌核发育二倍体鲫鲤具有正常的减数分裂过程并且其早期性腺存在着多倍体卵原细胞。     

芒果SEPALAATA基因的克隆与表达分析

以芒果品种‘吕宋’(Mangifera indica L.Carabao)为试材,利用同源克隆和RACE技术从花序中获得了1个芒果SEPALAATA(SEP)基因cDNA全长,命名为MSEP1(GenBank中登录号为KP702299)。MSEP1基因的cDNA全长为921bp,包含一个长度为726bp开放阅读框,编码241个氨基酸,蛋白质相对分子质量为27.7kD,理论等电点为5.79。序列比对和系统进化树分析表明,MSEP1具有保守的MADS-box及半保守的K区,属于MADS-box家族的SEP亚家族。器官特异性表达分析表明,MSEP1基因在芒果根、茎中表达量较低,在叶片、花芽中表达量较高,而在花序中表达量最高。研究推测,MSEP1基因可能在芒果生殖生长中发挥重要作用。     

不同倍性鲫鲤鱼Dmc1基因cDNA的克隆 及其表达分析

酵母菌 Dmc1(disrupted meiotic cDNA)基因是一个在减数分裂前期Ⅰ表达的特异基因, 其产物是减数分裂同源染色体配对所必需的. 根据酵母菌、小鼠以及人的DMC1中保守氨基酸序列合成简并引物, 分别克隆了二倍体红鲫(Carassius auratus red var.)、湘江野鲤(Cyprinus carpio L.)、日本白鲫(Carassius cuvieri)、三倍体湘云鲫和异源四倍体鲫鲤Dmc1基因部分cDNA序列. 通过cDNA末端快速分离法(RACE)进一步获得了以上5种鱼Dmc1的cDNA全长, 其中红鲫Dmc1、湘江野鲤Dmc1和日本白鲫Dmc1全长均为1375 bp, 三倍体湘云鲫Dmc1全长1383 bp, 异源四倍体鲫鲤Dmc1全长1379 bp, 这5种鱼各自都编码342个氨基酸. 结果表明, 红鲫、湘江野鲤和日本白鲫的DMC1蛋白的氨基酸同源性高达97.3%, 说明DMC1蛋白在这3种鱼里具有高度保守性; 而三者与已知序列的人、小鼠和斑马鱼(Danio rerio)DMC1蛋白的氨基酸同源性分别为 86%, 86%和95%. 以分离得到的不同倍性鱼Dmc1基因编码区中完全相同的序列设计特异引物进行表达分析. RT-PCR结果表明, Dmc1只在性腺中表达, 在其他组织中不表达; 通过实时荧光定量PCR(real-time PCR), 对Dmc1基因在繁殖季节的二倍体红鲫, 三倍体湘云鲫, 四倍体鲫鲤性腺中的表达进行分析, 发现Dmc1在不同倍性鱼的性腺表达有差异, 在卵巢和精巢均表现为: 三倍体表达最高, 二倍体次之, 四倍体的表达最弱, 特别是在三倍体卵巢的表达远高于在二倍体和四倍体的表达. 同时, 对这3种鱼的性腺进行组织切片分析, 发现二倍体和四倍体鱼的性腺发育良好, 且四倍体成熟度高于二倍体, 而三倍体鱼性腺发育缓慢未达到性成熟, 特别是卵巢的发育相当不好. 由此可见, 在不同倍性鲫鲤鱼中Dmc1基因也是减数分裂特异的基因, 其表达与倍性无显著的相关性, 而与性成熟相关; 并且在三倍体卵巢中的过量表达可能与其减数分裂异常及其不育有关.     

不同倍性鲫鲤鱼Dmc1基因cDNA的克隆 及其表达分析

酵母菌 Dmc1(disrupted meiotic cDNA)基因是一个在减数分裂前期Ⅰ表达的特异基因, 其产物是减数分裂同源染色体配对所必需的. 根据酵母菌、小鼠以及人的DMC1中保守氨基酸序列合成简并引物, 分别克隆了二倍体红鲫(Carassius auratus red var.)、湘江野鲤(Cyprinus carpio L.)、日本白鲫(Carassius cuvieri)、三倍体湘云鲫和异源四倍体鲫鲤Dmc1基因部分cDNA序列. 通过cDNA末端快速分离法(RACE)进一步获得了以上5种鱼Dmc1的cDNA全长, 其中红鲫Dmc1、湘江野鲤Dmc1和日本白鲫Dmc1全长均为1375 bp, 三倍体湘云鲫Dmc1全长1383 bp, 异源四倍体鲫鲤Dmc1全长1379 bp, 这5种鱼各自都编码342个氨基酸. 结果表明, 红鲫、湘江野鲤和日本白鲫的DMC1蛋白的氨基酸同源性高达97.3%, 说明DMC1蛋白在这3种鱼里具有高度保守性; 而三者与已知序列的人、小鼠和斑马鱼(Danio rerio)DMC1蛋白的氨基酸同源性分别为 86%, 86%和95%. 以分离得到的不同倍性鱼Dmc1基因编码区中完全相同的序列设计特异引物进行表达分析. RT-PCR结果表明, Dmc1只在性腺中表达, 在其他组织中不表达; 通过实时荧光定量PCR(real-time PCR), 对Dmc1基因在繁殖季节的二倍体红鲫, 三倍体湘云鲫, 四倍体鲫鲤性腺中的表达进行分析, 发现Dmc1在不同倍性鱼的性腺表达有差异, 在卵巢和精巢均表现为: 三倍体表达最高, 二倍体次之, 四倍体的表达最弱, 特别是在三倍体卵巢的表达远高于在二倍体和四倍体的表达. 同时, 对这3种鱼的性腺进行组织切片分析, 发现二倍体和四倍体鱼的性腺发育良好, 且四倍体成熟度高于二倍体, 而三倍体鱼性腺发育缓慢未达到性成熟, 特别是卵巢的发育相当不好. 由此可见, 在不同倍性鲫鲤鱼中Dmc1基因也是减数分裂特异的基因, 其表达与倍性无显著的相关性, 而与性成熟相关; 并且在三倍体卵巢中的过量表达可能与其减数分裂异常及其不育有关.     

新基因人MOB cDNA的克隆与功能分析

人MOB基因被认为是在脑组织中高表达的5次跨膜而功能未知的膜蛋白.从胎儿和成人肾脏消减杂交cDNA文库中获得了一条新的表达序列标签（expressed sequence tag,EST）序列,该序列对应于功能未知的MOB基因.利用生物信息学分析工具和分子生物学技术,从胎儿肝脏中成功地克隆了人MOB基因cDNA序列,同时也获得了含有完整开放读码框的大鼠和鸡MOB的电子全长序列.人MOB基因定位于10q11.1～11.2之间,含有一个1 242 bp的开放阅读框,第415位开始的ATG可能是翻译起始位点.核酸序列相似性搜索发现,其他种属中存在与之高度相似的EST序列,如爪蟾（79%）、羊（87%）、猪（94%）、牛（93%）.蛋白质序列相似性搜索发现,人MOB与大鼠、小鼠和鸡MOB有97%、97%、91％的相似性,与其他一些不同种属来源的假想蛋白有45%～73%的相似性.不同物种之间MOB基因核酸和蛋白质序列的高度相似说明,MOB是进化上高度保守的蛋白质.保守结构域分析发现,人、小鼠、大鼠和鸡MOB结构域组成完全一致,N端均与不育α基序（sterile alpha motif,SAM）结构域显著匹配,随后出现匹配显著性稍差的几个结构域.核酸和蛋白质序列的保守性提示,除N端约70个氨基酸组成SAM结构域外,其余的保守氨基酸可能形成一个新的保守的MOB结构域.表达谱分析表明,人MOB基因在所有被检组织和细胞中都表达.亚细胞定位研究显示,人MOB广泛表达于细胞内,主要在细胞核.DNA含量测定结果表明,人MOB基因过表达并不影响HeLa细胞的细胞周期和凋亡.总之,人MOB蛋白是一个在多种组织和细胞中广泛表达、细胞内广泛分布、进化上十分保守的蛋白质,可能通过特定蛋白质之间的相互作用,参与多种发育过程的调节.其过表达不影响HeLa细胞的周期和凋亡.     

中华鲟铁蛋白基因cDNA全长克隆与组织表达分析

根据铁蛋白基因的保守序列,搜索GenBank数据库中华鲟的EST数据库得到一条同源序列.通过RT-PCR的方法对该序列进行扩增,修改其测序错误,获得中华鲟铁蛋白亚基cDNA全长,经过注释提交GenBank数据库,获取序列登录号EU348782.该cDNA长度为896bp,包含531bp的完整编码区,推测编码的蛋白质为176aa,分子量为20339.9Mr,理论等电点为5.66.它和大两洋鲑鱼铁蛋白序列同源性最高,达到82.9%.该基闪在中华鲟肝脏、胰脏、肌肉、脑、心脏、鳃和胃粘膜等多种组织表达,在胰脏和心脏中表达量较高,在肌肉组织中表达较低.根据同源模建的方法得到该蛋白质三维结构,其包括5个α螺旋和10个转角结构,和人、蛙和细菌的铁蛋白均能很好的叠合,表现了很高的相似性,表明该蛋白结构和功能在基因进化中的高度保守性.     

天祝白牦牛IGF-2基因的cDNA克隆

旨在克隆天祝白牦牛胰岛素样生长因子2(IGF-2)基因编码区全长cDNA序列,为研究该基因的生理功能奠定基础。运用cDNA末端快速扩增(RACE)技术获得天祝白牦牛IGF-2基因全长cDNA序列。扩增获得天祝白牦牛IGF-2基因全长cDNA序列为1 060 bp(GenBank登录号:KF682139),ORF长540 bp,编码179个氨基酸。其编码的氨基酸与已报道哺乳动物IGF-2氨基酸序列同源性在80%-92%之间。天祝白牦牛IGF-2基因的成功克隆为进一步研究该基因的功能奠定了基础。     

不结球白菜晚抽薹BcFLC3基因的克隆及表达分析

根据大白菜BcFLC3基因(GenBank登录号AY036890.1)保守域序列设计引物,扩增不结球白菜晚抽薹BcFLC3基因的核心片段,结合RACE技术获得该基因1 017 bp的全长cDNA序列.序列分析结果表明,该cDNA包含完整开放阅读框,编码197个氨基酸的蛋白质,其分子量为21.62 kD,等电点9.36.荧光定量 PCR分析表明,不结球白菜经4℃低温处理后,BcFLC3基因在叶片中的表达量抽薹前明显高于抽薹后;低温处理后BcFLC3基因在不同部位的表达量存在明显差异,表达量由高到低依次为叶、茎、花蕾、花和根.Southern杂交结果表明,BcFLC3基因在不结球白菜基因组中为多拷贝.     

内蒙古白绒山羊翻译控制肿瘤蛋白(TCTP)基因克隆及组织表达特性分析

旨在克隆内蒙古白绒山羊翻译控制肿瘤蛋白(Translationally controlled tumor protein,TCTP)基因并分析其表达模式。采用RT-PCR技术扩增TCTP基因编码区cDNA序列,将得到的基因cDNA序列及其编码的氨基酸序列进行生物信息学分析,利用定量RT-PCR方法检测TCTP基因在绒山羊不同组织中的表达特异性。获得的内蒙古白绒山羊TCTP基因编码区cDNA序列全长519 bp,包含了完整的ORF,编码172个氨基酸残基组成的蛋白质。核苷酸序列与绵羊、牛、猪、人、猴及大鼠的同源性在99%-95%之间。生物信息学分析表明,编码的蛋白质理论分子质量19.6 kD,等电点(pI)4.673,含有一个N端糖基化位点,一个蛋白激酶C磷酸化位点,3个酪蛋白激酶Ⅱ磷酸化位点,定位于细胞质中。定量RT-PCR方法检测表明,TCTP基因在绒山羊肾脏、肌肉、胰腺、肝脏、睾丸和脑组织中均有表达,其中在肝脏中的表达量较高,在脑中表达量较低。     

The cloning of Dmc1 cDNAs and a comparative study of its expression in different ploidy cyprinid fishes

Dmc1 (disrupted meiotic cDNA) is a functionally specific gene, which was firstly discovered in yeast and then found to encode a protein required for homologous chromosome synapsis during the process of meiosis. In this investigation, we cloned the partial cDNAs of Dmc1 of diploid red crucian carp, Japanese crucian carp, common carp, triploid crucian carp and allotetraploid hybrids by using a pair of degenerate primers based on the conservative sequence of amino acids of the DMC1 protein in yeast, mouse and human. The full length cDNAs were then obtained by rapid amplification of cDNA ends (RACE). Our data showed that the full length cDNAs of Dmc1 in the three diploid fishes are all 1375 bp long, while it is 1383 bp long in triploids and 1379 bp long in allotetraploids. And despite of the variation in length, all the cDNAs encode a protein of 342 amino acids. A high homology of 97.3% of the DMC1 protein can be drawn by comparing the amino acid sequences in the three diploids, which is also of 86%, 86% and 95% similarity to human, mouse and zebrafish, respectively. A comparative study of the expression pattern of Dmc1 was carried out by RT-PCR using specific primers against the same sequences of coding regions in different ploidy cyprinid fishes, from which it was showed that Dmc1 was expressed only in gonads of these five kinds of fishes. The expression pattern of Dmc1 in both ovaries and testes from different ploidy fishes within breeding season was also studied by Real-time PCR, and the results showed that the expression of this gene was greatly different among the three different ploidy fishes, which was the highest of triploid and lowest of allotetraploids. The histological sections data showed matured gonads of both diploid red crucian carp and allotetraploids in breeding season, although the latter demonstrated a higher maturation, and no gonadal maturation could be observed in triploids. In conclusion, we suggest that Dmc1 is specifically expressed in the period of meiosis in all the ploidy cyprinid fishes and directly related with the development of gonad in a manner of ploidy-independent way. And further, the high expression of Dmc1 in female triploids might be associated with abnormal meiosis and sterility.     

The cloning of Dmc1 cDNAs and a comparative study of its expression in different ploidy cyprinid fishes

Dmc1 (disrupted meiotic cDNA) is a functionally specific gene, which was firstly discovered in yeast and then found to encode a protein required for homologous chromosome synapsis during the process of meiosis. In this investigation, we cloned the partial cDNAs of Dmc1 of diploid red crucian carp, Japanese crucian carp, common carp, triploid crucian carp and allotetraploid hybrids by using a pair of degenerate primers based on the conservative sequence of amino acids of the DMC1 protein in yeast, mouse and human. The full length cDNAs were then obtained by rapid amplification of cDNA ends (RACE). Our data showed that the full length cDNAs of Dmc1 in the three diploid fishes are all 1375 bp long, while it is 1383 bp long in triploids and 1379 bp long in allotetraploids. And despite of the variation in length, all the cDNAs encode a protein of 342 amino acids. A high homology of 97.3% of the DMC1 protein can be drawn by comparing the amino acid sequences in the three diploids, which is also of 86%, 86% and 95% similarity to human, mouse and zebrafish, respectively. A comparative study of the expression pattern of Dmc1 was carried out by RT-PCR using specific primers against the same se-quences of coding regions in different ploidy cyprinid fishes, from which it was showed that Dmc1 was expressed only in gonads of these five kinds of fishes. The expression pattern of Dmc1 in both ovaries and testes from different ploidy fishes within breeding season was also studied by Real-time PCR, and the results showed that the expression of this gene was greatly different among the three different ploidy fishes, which was the highest of triploid and lowest of allotetraploids. The histological sections data showed matured gonads of both diploid red crucian carp and allotetraploids in breeding season, although the latter demonstrated a higher maturation, and no gonadal maturation could be observed in triploids. In conclusion, we suggest that Dmc1 is specifically expressed in the period of meiosis in all the ploidy cyprinid fishes and directly related with the development of gonad in a manner of ploidy-independent way. And further, the high expression of Dmc1 in female triploids might be associ-ated with abnormal meiosis and sterility.     

银鲫与彩鲫卵母细胞cDNA文库构建及周期蛋白A1的cDNA克隆

分别取行天然雌核发育繁殖的银鲫和两性生殖的彩鲫的卵母细胞为材料,提取总RNA,分离mRNA,进而反转录合成cDNA并定向插入λgtll Sfi-Not克隆载体,经体外包装构建了银鲫与彩鲫卵母细胞的表达型cDNA文库。测试结果表明库容量分别达到3.1×106(银鲫)和1.6×106(彩鲫)。进一步人工合成Cyclin A1保守引物,采用PCR扩增文库的方法,克隆了银鲫(1616bp)与彩鲫(1626bp)的Cyclin A1全长cDNA。序列分析结果表明:两种鱼编码区长度均为1173bp,起始于一个包含在脊椎动物起始密码子ANNATG基元内ATG的单一开放读码框,编码391个氨基酸;5'-端非编码区长度也同为70bp,3-'端非编码区长度略有不同,银鲫为373bp,而彩鲫则为383bp;二者3'-端均带有AATAAA的Poly(A)加尾信号以及24bp(银鲫)和27bp(彩鲫)的Poly(A)尾巴。比较银鲫、彩鲫和金鱼与人、爪蟾Cyclin A1氨基酸序列同源性的结果表明,Cyclin A1在人、爪蟾与鱼类之间具有较高同源性;而在银鲫、彩鲫和金鱼之间,Cyclin A1仅在周期蛋白框外存在5个氨基酸的差异,且这些差异均是由个别碱基的变异造成的。       

从ATPase8-6基因研究杂交多倍体鱼线粒体母性遗传

异源四倍体鲫鲤是世界上首例人工培育的两性可育并形成群体的且能自然繁殖的四倍体鱼。本文采用质粒克隆测序法测定了红鲫、异源四倍体鲫鲤、三倍体湘云鲫和三倍体湘云鲤的ATPase8和ATPase6基因全序列 ,结合鲤鱼、日本白鲫和斑马鱼的同源序列 ,对不同倍性水平鲤科鱼类的ATPase8和ATPase6基因进行了比较 ,分析了碱基组成、变异情况以及核苷酸和氨基酸序列差异。红鲫、鲤鱼、异源四倍体鲫鲤、日本白鲫、三倍体湘云鲫和三倍体湘云鲤之间的序列差异为 0 0 % - 1 3 4 % ,它们与外群斑马鱼之间的序列差异为 2 7 9% -31 0 %。用MEGA软件中的MP法、ME法、NJ法和UPGMA法构建分子系统树 ,得到了相似的拓扑结构。结果分析表明 ,人工杂交多倍体异源四倍体鲫鲤、三倍体湘云鲫和三倍体湘云鲤在线粒体ATPase8和ATPase6基因上具有严格的母性遗传特征。值得注意的是 ,异源四倍体鲫鲤经过 1 1代的繁育后 ,与其原始母本红鲫仍然保持了非常高的同源性 ,说明了新的异源四倍体基因库在线粒体ATPase8和ATPase6基因上拥有稳定的遗传特性。对不同倍性鲤科鱼类线粒体ATPase8和ATPase6基因的研究表明 ,ATPase8和ATPase6基因是杂交鱼后代遗传变异研究的一个很好的分子标记     

异源四倍体鲫鲤、三倍体湘云鲫和它们父母本线粒体DNA 12S rRNA基因遗传变异的分析

采用质粒克隆测序方法,获得了异源四倍体鲫鲤5个个体、异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体及红鲫、湘江野鲤和日本白鲫各1个个体的线粒体DNA 12S rRNA基因的全序列。经对比发现,异源四倍体5个个体共享2种单元型,异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体以及红鲫、湘江野鲤和日本白鲫各1个个体分别共享1种单元型。用MEGA 1.0 软件分析了它们的碱基组成和核苷酸序列差异,用邻接法构建系统进化树。它们间的序列同源性在95%~99%之间,异源四倍体鲫鲤、三倍体湘云鲫和它们母本（分别为红鲫和日本白鲫）之间的序列同源性大于异源四倍体鲫鲤、三倍体湘云鲫和它们父本（分别为湘江野鲤和异源四倍体鲫鲤）之间的序列同源性,结果表明：异源四倍体鲫鲤和三倍体湘云鲫在线粒体DNA 12S rRNA基因上具有母性遗传特征。本研究另一值得注意地方的是异源四倍体鲫鲤经过9代(F3-F11)繁殖后,在5个个体中发现了2种单元型,说明在四倍体基因库中存在遗传多样性,为四倍体基因库的繁殖、保护和种群复壮提供了一些有价值的信息。     

Molecular cloning and characterization of alpha-class glutathione S-transferase gene from the liver of silver carp, bighead carp, and other major Chinese freshwater fishes

Two full-length cDNAs encoding glutathione S-transferase (GST) were cloned and sequenced from the hepatopancreas of planktivorous silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). The silver carp and bighead carp GST cDNA were 920 and 978 bp in length, respectively, and both contained an open reading frame that encoding 223 amino acids. Partial GST cDNA sequences were also obtained from the liver of grass carp (Ctenopharyngodon idellus), crucian carp (Carassius auratu), mud carp (Cirrhinus molitorella), and tilapia (Oreochromis nilotica). All these GSTs could be classified as alpha-class GSTs on the basis of their amino acid sequence identity with other species. The three-dimensional structure of the silver carp GST was predicted using a computer program, and was found to fit the classical two-domain GST structure. Using the genome walker method, a 875-bp 5'-flanking region of the silver carp GST gene was obtained, and several lipopolysaccharide (LPS) response elements were identified in the promoter region of the phytoplanktivorous fish GST gene, indicating that the GST gene expression of this fish might be regulated by LPS, released from the toxic blue-green algae producing microcystins. To compare the constitutive expression level of the liver GST gene among the six freshwater fishes with completely different tolerance to microcystins, beta-actin was used as control and the ratio GST/beta-actin mRNA (%) was determined as 130.7 +/- 6.6 (grass carp), 103.1 +/- 8.9 (bighead carp), 92.6 +/- 15.0 (crucian carp), 72.3 +/- 7.8 (mud carp), 58.8 +/- 11.5 (silver carp), and 33.6 +/- 13.7 (tilapia). The constitutive expression level of the liver GST gene clearly shows that all the six freshwater fishes had a negative relationship with their tolerance to microcystins: high-resistant fishes (phytoplanktivorous silver carp and tilapia) had the lowest tolerance to microcystins and the high-sensitive fish (herbivorous grass carp) had the highest tolerance to microcystins. Taken together with the reciprocal relationship of constitutive and inducible liver GST expression level in some of the tested fish species to microcystin exposure, a molecular mechanism for different microcystin detoxification abilities of the warm freshwater fishes was discussed.     

Comparative and Evolutionary Analysis of the Cytochrome b Sequences in Cyprinids with Different Ploidy Levels Derived from Crosses

The mitochondrial cyt b genes in the allotetraploid and triploid crucian carp as well as triploid common carp were isolated and completely sequenced. Their DNA sequences were compared with those derived from the cyt b genes of the red crucian carp, Japanese crucian carp, and common carp with MEGA 1.0 software. Phylogenetic analysis revealed the sister relationships between allotetraploid and diploid red crucian carp, between the triploid crucian carp and diploid Japanese crucian carp, and between triploid common carp and diploid common carp. Our results indicated the cyt b genes in the allotetraploid, triploid crucian carp, and triploid common carp were maternally inherited. Through maternal inheritance, the cyt b gene in the F11 tetraploid displayed extremely high similarity to that in the female parent red crucian carp after 11 generations (from F1 to F11 hybrids). Since the establishment of the new tetraploid stocks has great significance in analyzing evolutionary theory of vertebrate and in improving aquaculture industry, analysis of the cyt b gene and the elucidation of the variation of the cyt b gene DNA in different cyprinids prove that cyt b is a useful genetic marker to monitor the variations in the progeny of the crosses.     

Differential screening and characterization analysis of the egg envelope glycoprotein ZP3 cDNAs between gynogenetic and gonochoristic crucian carp

INTRODUCTIONFertilization in animals is the trigger that ini-tiates development, and results in a series of well-choreographed interactions between molecules lo-cated on the surfaces of egg and sperm[1, 2]. Somecell surface proteins, such as zolla pellucida gly-coprotein ZPI, ZPZ and ZP3, acrosomal proteinbindin, acrosin and lysin, and sperm plasma mem-brane protein a- and p--fertilin, have been identi-fied to mediate the interaction process[2-8]. Al-though studies on the regulative fa…