基于RNA-Seq数据识别果蝇剪接位点和可变剪接事件

完整基因结构的预测是当前生命科学研究的一个重要基础课题,其中一个关键环节是剪接位点和各种可变剪接事件的精确识别.基于转录组测序（RNA-seq）数据,识别剪接位点和可变剪接事件是近几年随着新一代测序技术发展起来的新技术策略和方法.本工作基于黑腹果蝇睾丸RNA-seq数据,使用TopHat软件成功识别出39718个果蝇剪接位点,其中有10584个新剪接位点.同时,基于剪接位点的不同组合,针对各类型可变剪接特征开发出计算识别算法,成功识别了8477个可变剪接事件（其中新识别的可变剪接事件3922个）,包括可变供体位点、可变受体位点、内含子保留和外显子缺失4种类型.RT-PCR实验验证了2个果蝇基因上新识别的可变剪接事件,发现了全新的剪接异构体.进一步表明,RNA-seq数据可有效应用于识别剪接位点和可变剪接事件,为深入揭示剪接机制及可变剪接生物学功能提供新思路和新手段.

Identification of Novel Splice Sites and Alternative Splicing Events in Drosophila melanogaster Using RNA-seq Data

Gene structure prediction is the first and most fundamental step to genome analysis and annotation. Splice site and alternative splicing (AS) prediction is particularly challenging for eukaryotes. With the Next Generation sequencing technologies, RNA-seq has been used in identification of splice site and alternative splicing. In this work, 39718 fruit fly splice sites were identified based on Drosophila melanogaster testis RNA-seq data by using Tophat software, of which 10584 were new discoveries. By different donor/acceptor splice site combinations, a computational identification method has been developed and applied to predict 8477 alternative splicing events (containing four distinct classes of AS events: alternative donor site, alternative acceptor site, intron retention and exon skipping). RT-PCR successfully validated novel alternative splicing events and new isoforms in two genes. Our result indicates that RNA-seq was not only an effective and accurate method for splice site and AS event detection, but also a new technique for deciphering molecular mechanism of RNA splicing further.