rRNA二级结构序列用于真菌系统学研究的方法初探(英文)  

An attempt to use rRNA secondary structure characters in fungal systematics

作　　者：刘超洋[1,2] 庄文颖[1] 

机构地区：[1]中国科学院微生物研究所真菌地衣系统学重点实验室 [2]中国科学院研究生院,北京100039

出　　处：《菌物学报》2007年第1期22-31,共10页Mycosystema

基　　金：National Natural Science Foundation of China (no. 30230020, 30470009)

摘　　要：本文首次利用核酸二级结构特征代替核酸碱基作为探讨类群之间亲缘关系的信号,构建了基于结构特征的子囊菌部分类群的系统进化树。该方法以S(规范的碱基对),Q(不规范的碱基对),I(单链),B(侧环),M(多分枝环)和H(发卡结构)为代码将二级结构特征区分为6种不同的亚结构类型,然后将二级结构特征转换为结构序列,并进行结构序列分析。该方法使rRNA不只局限于碱基比较,拓展了其应用范围,为揭示分子的功能与进化的关系提供了线索。结果表明,结构序列分析可用于子囊菌的系统学研究;相对于核酸序列分析,结构分析的结果似乎更加清晰地体现子囊果的演化过程。A new approach using sequences of secondary structure to assess phylogenetic relationships is introduced. The descriptive dimensional positions of bases instead of sequences of nucleic acids are used as specific characters to construct a phylogenetic tree. Application of the method to phylogenetic analysis of selected taxa of Ascomycota at different taxonomic ranks indicates that structure signal is useful for exploring the phylogenetic relationships among groups. As a proof,the nucleotide signal with the same informative sites was also performed. Comparison between the structure trees and nucleotide trees revealed that structure analysis gives stronger support to classification based on morphological features and to phylogeny established by RPB2 sequence analysis. The method extends the application of rRNA molecule,which makes analysis based on rRNA sequences not limited to base comparison and is complementary to primary sequence analysis in fungal phylogenetic studies.

关 键 词：子囊菌门 亚结构类型 结构序列 系统演化信号 

分 类 号：Q949.32[生物学—植物学] Q931