基于rDNA ITS序列研究蚌科6种类的系统发生关系

The Phylogenetic Analysis of 6 Bivalvia Species(Unionidae)Based on the Sequences of Ribosomal DNA Internal Transcribed Spacer

通过测定核糖体转录间隔区ITSI以及ITS2序列研究了江苏地区蚌科（Unionidae）6种常见贝类——褶纹冠蚌（Cristaria plicata）、三角帆蚌（Hyriopsis cumingii）、背角无齿蚌（Anodneta woodiana woodiana）、扭蚌（Arconaia lanceolata）、圆顶珠蚌（Unio douglasiae）以及背瘤丽蚌（Lamprotula leui）的系统发生关系．结果显示：6种蚌的ITSI序列长度介于354～439bp之间，平均G＋C百分含量为52．7％；ITS2序列长度介于287～354bp之间，平均G＋C百分含量为512％．对6种贝类的相关序列进行比对，ITSI的比对长度包括501个位点，其中有364个变异位点和99个简约信息位点；ITS2的比对长度包括381个位点，其中有259个变异位点和66个简约信息位点。以虾夷扇贝（Mizuhopecten yessoensis）为外群，采用邻接法（NJ）分析6种贝类的系统发生关系，贝类明显聚合为3个类群：类群Ⅰ包括三角帆蚌（H．caulingu）和背瘤丽蚌（L．leai）．类群Ⅱ包括扭蚌（A．lanceolata）和圆顶珠蚌（U．douglasiae），类群Ⅲ由背角无齿蚌（A．woodiana uoodiana）和褶纹冠蚌（C．plicata）组成。

This study presents the ribosomal DNA internal transcribed spacer region sequences （ITS1 and ITS2）of 6 bivalvia species（ Unionidae ： Cristaria plicata ; Hyriopsis cumingii ; Anodneta woodiana woodiana ; Arconaia lanceolata ; Unio douglasiae and Lamprotula leai）which were all collected from Jiaugsu Province. The length of ITSI ranges from 354 bp to 439 bp, with average G ＋ C content of 52.7%. The length of ITS2 ranges from 287 bp to 354 bp, with average G ＋ C content of 51.2%. The alignment length of the ITS1 sequence is 501 , including 364 variable sites and 99 parisimony informative sites. The alignment length of the ITS2 sequence is 381, including 259 variable sites and 66 parisimony informative sites. Phylogenetic analysis by the methods of Neighbor-Joining（ NJ ）was employed to reconstruct the phylogeny with Mizuhopecten yessoensis designated as outgroup. The result shows that the species in the study constitute three clades： clade Ⅰ with H. culingii and L. leai, clade Ⅱ with A. lanceolata and U. douglasiae, elade Ⅲ with A. woodiana woodiana and C. plicata.