GenBank数据库中微生物rDNA序列准确性研究

摘要

rDNA序列同源性分析是目前常用的一种微生物分子鉴定方法。在该方法中,待鉴定微生物的rDNA序列需要与GenBank数据库中的相关序列进行同源性比对,从而得出该菌株的具体种属。从GenBank数据库中收集了细菌16S rDNA序列、丝状真菌ITS序列以及酵母26S rDNA D1/D2区域序列共88条,通过BLAST比对和构建系统发育树的方法对所收集rDNA序列的准确性进行了验证。结果发现有17条序列（19.3%）的长度过短,无法提供足够的系统发育信息;5条序列（5.6%）存在错误命名或测序不准确问题;58条序列（65.9%）没有相关文章发表;62条序列（70.4%）无法获取对应的微生物保藏物。从而提示了GenBank数据库的有限参考价值,在微生物分子鉴定过程中需要对相关rDNA序列的准确性进行验证。%rDNA sequence-based analysis has been widely used in microbial identification.This study verified the accuracy of the rDNA sequences data deposited in GenBank.Forty-three 16S rDNA sequences of Bacillus horikoshii,twenty-two ITS（internal transcribed spacer） sequences of Aspergillus foetidus and twenty-three 26S rDNA D1/D2 region sequences of Candida boidinii were obtained from GenBank database.The result showed that out of these 88 named sequences,5 were misidentified or unreliable,17 were incomplete and too short to align,58 were unpublished and 62 were unvouchered in public collections.This study suggests that the GenBank database provided limited reference value in the microbial rDNA homology.The accuracy of related sequences needs to be verified by BLAST analysis.