梨Ty1-copia类反转录转座子GAG开放阅读框预测和光响应下的表达分析

基于生物信息学方法，对‘砀山酥梨’基因组中Ty1-copia类型的GAG开放阅读框进行预测，共获得315条GAG序列。通过系统聚类，梨基因组中GAG序列可分为7个支系，第一和第三支系成员较多且保守性高。序列比对结果显示，不同支系GAG序列具有较高的异质性。在‘美人酥’梨的套袋和摘袋后的果皮中发现了34个gag成员，其中有6个（Ppgag16、Ppgag19、Ppgag23、Ppgag27、Ppgag29和Ppgag30）为高丰度表达成员。遮光条件下，‘美人酥’果皮中有部分gag成员发生表达，说明copia类反转座子不仅仅受光照影响发生表达。在摘袋后，‘美人酥’果皮中有2个成员（Ppgag5和Ppgag23）发生明显上调表达，说明梨中部分反转录转座子的转录受到光照的调控。

Prediction of ORF for GAG of Ty1-copia Retrotransposons in Pear and Its Expression Analysis in Response to Light

Different types of sequences of ORF for GAG in the whole genome of‘Dangshan Suli’（Pyrus pyrifolia White Pear Group）were predicted by bioinformatics methods. A total of 315 GAGsequences were obtained from Ty1-copia retrotransposons. The cluster analysis indicated that there were seven groups，among which，groups one and three had many conserved members. Sequence alignment of all GAG sequences in pear genome showed a high heterogeneity. A total of 34 members were expressed in bagging and bag-removed‘Meirensu’pear fruit，of which，six members（Ppgag16，Ppgag19，Ppgag23，Ppgag27，Ppgag29，and Ppgag30）were highly expressed. In bagging-treated fruit，some members of gag were expressed，suggesting that lightwas not a sole factor to activatethe expression of copia retrotransposons. In bag-removed fruit，the expression of two members（Ppgag5 and Ppgag23）were up-regulated，indicating that some members of the retrotransposons were regulated by light.