CAJ | 학술논문

研究旨在测定隶属桡足亚纲(Copepoda)杯口水蚤目(Poicilostomatoida)的寄生甲壳动物鲢中华鳋(Sinergasilus polycolpus)线粒体DNA(mtDNA)序列,分析其结构特征,为节肢动物系统进化研究积累资料.利用简并引物扩增鲢中华鳋Cyt b和CO I基因片断,据此设计特异性引物Long-PCR扩增鲢中华鳋mtDNA序列,拼接后得到12917 bp的序列(GenBank登录号为EU621723).这段序列A、T、C、G碱基含量分别为35.0%、35.8%、14.0%和15.2%,GC-Skew和AT-Skew值分别为0.041和-0.011.通过序列同源性和结构分析,鉴定了35个基因,包括13个蛋白编码基因、21个tRNA基因和1个12s rRNA基因.推测未能扩增到的片段包含16S rRNA、tRNA~(Arg)和tRNA~(Thr)基因以及控制区序列.tRNA基因长度在54-63bp之间,均可折叠成典型的三叶草结构,但TψC臂长度变化较大,其中有三个缺少TψC臂.35个基因中.4个蛋白质编码基因和7个tRNA基因位于N链,其余的位于J链.基因间重叠有12处,重叠碱基量达159 bp.进一步研究桡足类及相关类群线粒体基因组的遗传特征将有助于揭示和阐明桡足类系统发育关系.
연구지재측정대속뇨족아강(Copepoda)배구수조목(Poicilostomatoida)적기생갑각동물련중화소(Sinergasilus polycolpus)선립체DNA(mtDNA)서렬,분석기결구특정,위절지동물계통진화연구적루자료.이용간병인물확증련중화소Cyt b화CO I기인편단,거차설계특이성인물Long-PCR확증련중화소mtDNA서렬,병접후득도12917 bp적서렬(GenBank등록호위EU621723).저단서렬A、T、C、G감기함량분별위35.0%、35.8%、14.0%화15.2%,GC-Skew화AT-Skew치분별위0.041화-0.011.통과서렬동원성화결구분석,감정료35개기인,포괄13개단백편마기인、21개tRNA기인화1개12s rRNA기인.추측미능확증도적편단포함16S rRNA、tRNA~(Arg)화tRNA~(Thr)기인이급공제구서렬.tRNA기인장도재54-63bp지간,균가절첩성전형적삼협초결구,단TψC비장도변화교대,기중유삼개결소TψC비.35개기인중.4개단백질편마기인화7개tRNA기인위우N련,기여적위우J련.기인간중첩유12처,중첩감기량체159 bp.진일보연구뇨족류급상관류군선립체기인조적유전특정장유조우게시화천명뇨족류계통발육관계.
The mitochondrial genomes can provide useful information of the phylogenetic relationships among arthropod groups from two aspects, i.e. gene arrangement and mitochondrial DNA (mtDNA) sequence variation, however,there is no report on the mt genomes of species in the order Poicilostomatoida. The present study aims to determine the nucleotide sequence of mitochondrial geneme of Sinergasilus polycolpus, a poicilostomatoid copepod, parasitizing the freshwater fish Hypophthalmichthys raolitrix and Aristichthys nobilis. The segments of Cyt b and CO I genes of S.polycolpus were amplified using the degenerate primers, which were designed on the basis of the homologous sequences.Then the special primers were designed on the above segments to amplify the long mtDNA sequence with Long-PCR.Finally, a mtDNA sequence of 12917 bp in length was gotten from S. polycolpus, and deposited in the GenBank database with the accession number of EU621723. This sequence was composed of A of 35.0%, T of 35.8%, C of 14.0% and G of 15.2%, and furthermore the GC-Skew and the AT-Skew were 0.041 and -0.011, respectively. According to the sequence homology and the structure characteristics, the total of 35 genes were identified, including one 12S rRNA, twenty-one tRNA and thirteen protein-coding genes. However, the amplification for the segment containing putative 16S rRNA,tRNA~(Arg)and tRNA~(Thr)genes and control region was unsuccessful. The 13 protein-coding genes had ATA, ATG, ATC and ATT as initiation codons, and TAA, TAG, TA and T as termination codons, respectively. TA and T were incomplete termination codons. All the 21 tRNA genes, ranging between 54 and 63 bp in length, could be folded to form the figure of clover leaf knot. However, other than 3 tRNA genes without TψC ann, the length of TψC arms of tRNA genes varied from lbp to 4bp. Of 35 genes, 4 protein-coding genes, i.e. CO I, NDS, Cyt b and ND4, and 7 tRNA genes, i.e.tRNA~(Leu(CUN)), tRNA~(Met), tRNA~(Pro), tRNA~(Asp), tRNA~(Glu), tRNA~(Tyr)and tRNA~(His), were encoded on the N strand, the remainders on the J strand. In addition, 12 gene overlapping sites were found in the Sinergasilus polycolpus mtDNA, hut the significance of gene overlapping in the copepod mt genomes was incompletely clear. In order to elucidate the phylogeny of the copepods, it is necessary to study the mt genomes of more copepods as well as other related groups.