基于28S rDNA基因序列研究十种臂尾轮虫的系统关系和分类地位

PHYLOGENETIC RELATIONSHIP AND TAXONOMIC STATUS OF TEN BRACHIONUS SPECIES (ROTIFERA) INFERRED FROM 28S rDNA GENE

通过对角突臂尾轮虫、尾突臂尾轮虫、裂足臂尾轮虫、剪形臂尾轮虫、方形臂尾轮虫、壶状臂尾轮虫、红臂尾轮虫、镰形臂尾轮虫、萼花臂尾轮虫和十指臂尾轮虫等10种臂尾轮虫以及透明囊足轮虫、大肚须足轮虫和晶囊轮虫等其他3种轮虫的28SrDNA序列分析,使用MAGE软件构建这13种轮虫系统发生树(NJ树、ME树、UPGMA树和MP树),探讨了臂尾轮属、须足轮属、晶囊轮属和囊足轮属之间以及10种臂尾轮虫之间的系统关系。结果表明,本研究所涉及的轮虫28SrDNA序列差异百分比均值为30.15%,可作为分子标记应用于轮虫属间和属内种间系统关系研究;系统树均支持将十指臂尾轮虫作为一个独立的支系从臂尾轮属中分离出来;裂足臂尾轮虫应隶属臂尾轮属;壶状臂尾轮虫和红臂尾轮虫是两个独立的种;透明囊足轮虫与臂尾轮属亲缘关系较近。

Partial portions of 28S rDNA gene from B. angularis, B. caudatus, B. diversicornis, B. forficula, B. quadridentatus, B. urceolaris, B. rubens, B. falcatus, B. calyciflorus, B. patulus, Asplanchnopus hyalinus, Euchlanis dilatata and Asplanchna sp. were amplified and sequenced, and neighbor-joining （NJ）, minimum-evolution （ME）, maximal parsimoniousness （MP） and unweighted pair-group method using an arithmetic average （UPGMA） methods were used with MAGE software to reveal their phylogenetic relationships and resolve some taxonomy questions. The results showed that the percentage of divergence for 28S rDNA gene sequences in 13 samples was 30.15%. 28S rDNA gene was suitable for researching the phylogenesis and evolutionary in rofifera. All the four trees showed that B. patulus was separated into an independent clade from the genus Brachionus, the generic identity of B. diversicornis was confirmed to belong to the genus Brachionus, B. urceolaris and B. rubens were two different species. Asplanchnopus hyalinus was more closely related to Brachionus than Asplanchna sp..