燕麦EST数据库中Ty1-copia和Ty3-gypsy型反转录转座子的频数分析

为研究转座元件(Transposable elements,TES)在燕麦中的表达模式,以14个Ty1-copia型反转录转座子和3个Ty3-gypsy型反转录转座子序列为种子序列对燕麦属(Avena)表达序列标签(EST)数据库中的Ty1-copia和Ty3-gypsy型反转录转座子进行检索和分析。结果表明:燕麦根中反转录转座子的频率显著高于叶(P0.05);强降雨模式的胁迫环境下叶组织中反转录转座子的EST频率显著高于大气降雨下的(P0.05),约为正常条件下的(Ee-10,0.12%)2倍;Ty1-copia和Ty3-gypsy型反转录转座子在根的分蘖期频率差异极显著(P0.01)。这些结果揭示了燕麦属Ty1-copia和Ty3-gypsy型反转录转座子的转录存在组织和发育的时空特异性及环境应答现象,为预测重复元件的表达模式提供了依据。同时,检索到的反转录转座子也有助于对燕麦基因组序列的注释。

Frequencies of Ty1-copia and Ty3-gypsy retroelements within the Avena EST database

To investigate the expression pattern of Transposable elements (Transposable elements,TE_S) in oat,fourteen Ty1-copia-type retrotransposon sequences and three Ty3-gypsy-type retrotransposon sequences were selected as seeded sequence to mine and analyse Ty1-copia-type and Ty3-gypsy-type retrotransposons in the Avena EST dababase of GenBank.The result showed the frequency of retrotransposons in root tissues was significantly higher (P<0.05) than in leaves.The frequency of retrotransposons in oat under high rainfall stress conditions (0.24% at E-10) was about to 2 folds higher than that of under ambient rainfall conditions (0.12% at E-10).The significant difference was estimated between Ty1-copia-type and Ty3-gypsy-type retrotransposons in root (P<0.01),but lack of significant differences in leaf.The result above suggested tissue-specific,developmental regulation and responses to the environment were existed in Ty1-copia-type and Ty3-gypsy-type retrotransposons of oat,which provided an indirect estimation of the patterns of transcriptional activity of these repetitive elements.The retrotransposons mined in Avena EST dababase are helpful to annotation of genomic sequences also.