基于18S rRNA基因序列分析唇口目苔藓动物主要类群的系统发生关系  

MOLECULAR PHYLOGENETIC RELATIONSHIPS OF THE CHEILOSTOMATOUS BRYOZOANS BASED ON 18S RRNA GENE SEQUENCES

作　　者：焦晓霞[1] 杨群[2] 赵华斌[1] 石庆会[1] 郝家胜[1,2] 

机构地区：[1]安徽师范大学生命科学学院,安徽芜湖241000 [2]中国科学院南京地质古生物研究所,江苏南京210008

出　　处：《动物分类学报》2009年第3期513-521,共9页Acta Zootaxonomica Sinica

基　　金：安徽省优秀青年基金(08040106811);国家自然科学基金(40202001);安徽省"重要生物资源保护与利用"重点实验室及中青年学术带头人专项基金(590620);安徽师范大学生物大分子重点实验室开放课题基金(2006A001);安徽省高校"生物环境与生态安全"省级重点实验室专项基金资助课题资助

摘　　要：对隶属于3亚目、5次目、20科、23属共25个种类的唇口目(裸唇纲)苔藓虫18SrRNA基因部分序列进行了序列测定。结合从GenBank中获得的该类群其它7个种类的18SrRNA基因同源序列,以序列分析软件对其序列组成和变异进行了比较分析;同时,以羽苔虫(被唇纲)和管孔苔虫(窄唇纲)为外类群,以邻接法和最大简约法重建了它们的系统发生树,分析了该目主要类群系统发生关系。序列分析结果显示:经比对后序列长度为884bp,其中保守位点241个,可变位点643个,简约信息位点357个;A,T,C和G4碱基平均含量分别为23.8%、22.8%、24.4%和28.9%。分子系统树表明:本研究所有有囊类构成1个单系群,其中胞次目的几种苔虫位于皮壳次目内部;无囊类形成1个多系群,其中的亚目级(新唇口亚目)和次目级分类阶元(枝室次目、假软壁次目和隐壁次目)也都为多系发生,这些结果与前人的分子系统学研究结果大体一致,而与传统的形态分类体系间存在明显的冲突。The partial 18S rRNA gene sequences of 25 examplar species which are subordinate to 23 genera,20 families,5 infraorders,3 suborders of the cheilostomatous bryozoans（class Gymnolaemata）were newly amplified and sequenced.Combining the homologous sequences of other seven species available from GenBank,their sequence composition and variations were compared and analyzed with sequence analyzing software and their phylogenetic trees were reconstructed with neighbor joining and maximum parsimony methods using Plumatella sp. （ class Phylactolaemata ） and Tubulipora flabellaris （ class Stenolaemata） as outgroups. The results of the sequence analyses showed that the aligned sequence is 884 bp in length, including 241 conserved, 643 variable and 357 parsimonious-informative sites, restively; the average percentages of the content of A, T, C, G are 23.8 %, 22.8%, 24.4% and 28.9%, respectively. The reconstructed phylogenetic trees showed that all the taxa of the suborder Ascophorina in this study is a monophyletic group, and within this group, the infraorder Umbonnlomorpha is scattered in the Leprafiomorpha; the Anasca is polyphylefic, within which the taxa of suborder Neocheilostomina and infraorders CeUulariomprpha, Psendomalacostoegomorpha and Cryptocystoomorpha are also polyphyletic, and these results are basically the same as those of former molecular phylogenetic studies, whereas they are in conflict with those based on traditional morphological classification system.

关 键 词：苔藓动物 唇口目 18S RRNA基因 系统发生 

分 类 号：Q951.1[生物学—动物学]