CAJ | 학술논문

该文测序了湾鳄的线粒体基因组全序列,全长为16,917 bp.湾鳄mtDNA结构与其他脊椎动物相似,由22个tRNA,2个rRNA和13个蛋白质编码基因及1个非编码的控制区(D-loop)所组成.除NADH6和tRNAGln、tRNAAla、tRNAAsn、tRNACys、tRNATyr、tRNASer(UCN)、tRNAGlu、tRNAPro在L-链上编码之外,其余基因均在H-链编码.基因排列顺序与己测序的鳄类一致,这显示了鳄类线粒体基因排列顺序上的保守性.但鳄类线粒体基因排列顺序与脊椎动物的典型排列方式相比,有较大的差异,尤其是tRNAPhe基因的重排、tRNASer-tRNAHis-tRNALeu基因族的排列方式等.湾鳄mtDNA和已测序的鳄类一样,缺失轻链复制起始点(OLR).基于17种鳄mtDNA控制区保守区,采用PAUP4.0最大简约法(Maximum parsimony,MP)构建MP树,邻接法(Neighbor-joining method,NJ)构建NJ树,结果显示:食鱼鳄(Gavialis gangeticus)和假食鱼鳄(Tomistoma schlegelii)聚为一支后再与鳄科(Crocodylidae)的其他物种形成姐妹群,这与基于食鱼鳄和假食鱼鳄的线粒体全序列的分析结果一致,支持将食鱼鳄并入鳄科的观点.结果还支持非洲窄吻鳄(Crocodylus cataphractus)与鳄属(Crocodylus)构成姐妹群,可以单独划分为属的观点.
해문측서료만악적선립체기인조전서렬,전장위16,917 bp.만악mtDNA결구여기타척추동물상사,유22개tRNA,2개rRNA화13개단백질편마기인급1개비편마적공제구(D-loop)소조성.제NADH6화tRNAGln、tRNAAla、tRNAAsn、tRNACys、tRNATyr、tRNASer(UCN)、tRNAGlu、tRNAPro재L-련상편마지외,기여기인균재H-련편마.기인배렬순서여기측서적악류일치,저현시료악류선립체기인배렬순서상적보수성.단악류선립체기인배렬순서여척추동물적전형배렬방식상비,유교대적차이,우기시tRNAPhe기인적중배、tRNASer-tRNAHis-tRNALeu기인족적배렬방식등.만악mtDNA화이측서적악류일양,결실경련복제기시점(OLR).기우17충악mtDNA공제구보수구,채용PAUP4.0최대간약법(Maximum parsimony,MP)구건MP수,린접법(Neighbor-joining method,NJ)구건NJ수,결과현시:식어악(Gavialis gangeticus)화가식어악(Tomistoma schlegelii)취위일지후재여악과(Crocodylidae)적기타물충형성저매군,저여기우식어악화가식어악적선립체전서렬적분석결과일치,지지장식어악병입악과적관점.결과환지지비주착문악(Crocodylus cataphractus)여악속(Crocodylus)구성저매군,가이단독화분위속적관점.
The nucleotide sequence of the complete mitochondrial DNA (mtDNA) molecule of the salt-water crocodile (Crocodylus porosus) was determined in this article. The molecule is 16,917 base pairs (bp) in length, and codes for 22 tRNAs, 13 protein-coding genes, 2 rRNAs, as well as a control region (D-loop), as is characteristic for mitochondrial genomes of other metazoans.The gene order conforms to that of other crocodilians sequenced, but the arrangement of some tRNA genes differs from other vertebrates. It shows that the gene order of crocodilians is remarkably conserved. In this study, the relationships among crocodilians were examined in the phylogenetic analysis based on the control conserved regions of 17 crocodilians. The results suggest that the gharial (Gavialis gangeticus) joins the false gharial (Tomistoma schlegelii) on a common branch, and then constitutes a sister group to traditional Crocodylidae. Thus, the result supports that G. gangeticus belongs to Crocodylidae. The analyses also suggest that the African slender-snouted crocodile (Crocodylus cataphractus) can be treated as an isolated genus, and constitutes a sister group to Crocodylus.