CAJ | 학술논문

文中探讨了线粒体COⅠ(线粒体细胞色素氧化酶Ⅰ)和16S rRNA基因片段的遗传特性及其在鳎科鱼类种类鉴定和系统演化中的适用性。通过测序和下载GenBank中的相关数据,分别获得了鳎科14属24种鱼类的65个个体的COⅠ基因片段以及14属23种鱼类的62个个体的16S rRNA基因片段。从碱基组成来看,除北海牛舌鳎(Buglossidium luteum)的16S rRNA序列中A+T含量为49.8%以外,其余种类的A+T含量均高于50%。COⅠ片段的碱基变异比例(约占45.5%)略高于16S rRNA片段(约占44.3%)。序列变异程度分析表明, COⅠ基因在种内和属内种间的平均K2P遗传距离分别为0.33%和19.91%,而16S rRNA的相应值分别为0.26%和7.19%。前者种内和种间的遗传差异约为60倍(个别最小相差19倍),符合Hebert的相差10倍的物种鉴定标准；后者种内和种间的差异也有28倍(个别最小差值为5倍)。因此, COⅠ和16S rRNA序列均适用于鳎科鱼类的种类鉴定。另外,2种基因片段的遗传距离在不同分类阶元的分布上存在重叠,由于COⅠ序列的遗传距离重叠区域存在于较高的阶元之间(种间、属、科),而16S rRNA序列的重叠区域存在于较低的阶元之间(种内、种间、属)。因此,在应用这2个片段做系统演化研究时,应根据研究的不同系统水平需要选择适当的分子标记。
문중탐토료선립체COⅠ(선립체세포색소양화매Ⅰ)화16S rRNA기인편단적유전특성급기재탑과어류충류감정화계통연화중적괄용성。통과측서화하재GenBank중적상관수거,분별획득료탑과14속24충어류적65개개체적COⅠ기인편단이급14속23충어류적62개개체적16S rRNA기인편단。종감기조성래간,제북해우설탑(Buglossidium luteum)적16S rRNA서렬중A+T함량위49.8%이외,기여충류적A+T함량균고우50%。COⅠ편단적감기변이비례(약점45.5%)략고우16S rRNA편단(약점44.3%)。서렬변이정도분석표명, COⅠ기인재충내화속내충간적평균K2P유전거리분별위0.33%화19.91%,이16S rRNA적상응치분별위0.26%화7.19%。전자충내화충간적유전차이약위60배(개별최소상차19배),부합Hebert적상차10배적물충감정표준；후자충내화충간적차이야유28배(개별최소차치위5배)。인차, COⅠ화16S rRNA서렬균괄용우탑과어류적충류감정。령외,2충기인편단적유전거리재불동분류계원적분포상존재중첩,유우COⅠ서렬적유전거리중첩구역존재우교고적계원지간(충간、속、과),이16S rRNA서렬적중첩구역존재우교저적계원지간(충내、충간、속)。인차,재응용저2개편단주계통연화연구시,응근거연구적불동계통수평수요선택괄당적분자표기。
This study investigated the genetic characteristics of mitochondrial COⅠ(mitochondrial cytochrome c oxidase subunitⅠ) and 16S rRNA gene fragments and their applicability in species identification and phylogeny of sole fish Through sequencing and downloading available data from the GenBank, we obtained COⅠgene fragments from 65 individuals of 24 species in 14 genera and 16S rRNA gene fragments from 62 individuals of 23 species in 14 genera of Soleidae, respectively. Results of base composition analysis showed that the A+T content was higher than 50%except for 16S rRNA sequence of B. luteum (49.8%). The proportion of variation base of COⅠ(about 45.5%) was a little higher than that of 16S rRNA (about 44.3%). Means of intraspecific and interspecific K2P genetic distances were respectively 0.33% and 19.91% for COⅠsequences, and 0.26% and 7.19% for 16S rRNA sequences. Genetic differences of COⅠsequences between congeners were, on average, about 60 times (minimum 19 times) higher than the differences within species, which met Hebert’s species identification standard (more than 10 times the difference between intraspecies and interspecies). Genetic differences of 16S rRNA sequences were 28 times between intraspecies and interspecies (minimum five times). Therefore, COⅠand 16S rRNA sequences were both applicable for species identification in sole fish. Moreover, there were overlaps in genetic distance distribution of the two gene fragments between different taxa. The overlap region in COⅠ-based genetic distance distribution existed in higher taxa (interspecies, genus, family), while that in 16S rRNA sequence existed in lower taxa (intraspecies, interspecies, genus) 16S rRNA. As a result, it is advisable to select appropriate molecular markers according to different classified levels when applying the two gene fragments for studying systematic evolution.