Digital Gene Expression Analysis Based on Integrated De Novo Transcriptome Assembly of Sweet Potato [Ipomoea batatas (L.) Lam.]

More than 3.5 million raw DGE tags were obtained in each library. The clean tags in each sample ranged from 3.35 to 3.63 million, and the distinct clean tags ranged from 93,593 to 139,389. The 21 bp DGE clean tags were mapped to sweet potato transcripts. Then, we compared 7 libraries pair-wisely so that 21 pairs of comparisons were implemented. Among these comparisons, we found that 4,721 to 12,151 transcripts had significant changes in expression, and the average number was 9,657. We also observed a large number of specifically expressed transcripts between each two libraries. The expression profiles of those genes involved in root development and carbohydrates accumulation were characterized. Moreover, other genes of interest, such as potentially abiotic stress tolerance and insect resistance, were also characterized. 7 samples are examined: young leaves, mature leaves, stems, fibrous roots, initial tuberous roots, expanding tuberous roots and harvest tuberous roots.每个测序文库均获得超过350万条原始数字基因表达谱（Digital Gene Expression, DGE）标签。各样本的洁净标签数量介于335万至363万之间，唯一洁净标签数量则处于93593至139389的区间内。将21 bp的DGE洁净标签比对至甘薯转录本序列。随后，我们对7个文库进行两两比对，共完成21组对比分析。在上述对比中，共有4721至12151条转录本出现显著表达差异，平均差异表达转录本数量为9657。同时，我们还在每两个文库间发现了大量特异性表达的转录本。对参与根系发育与碳水化合物积累的基因的表达谱进行了特征分析。此外，其他潜在具有非生物胁迫耐受性与抗虫性的目标基因，也完成了特征解析。本研究共检测7类样本：幼叶、成熟叶、茎、须根、初始块根、膨大期块根及收获期块根。