PacBio full-length transcriptome profiling of insect mitochondrial gene expression

In this study, we sequenced the first full-length insect transcriptome using the Erthesina fullo Thunberg based on the PacBio platform. We constructed the first quantitative transcription map of animal mitochondrial genomes and built a straightforward and concise methodology to investigate mitochondrial gene transcription, RNA processing, mRNA maturation and several other related topics. Most of the results were consistent with the previous studies, while to the best of our knowledge some findings were reported for the first time in this study. The new findings included the high levels of mitochondrial gene expression, the 3′ polyadenylation and possible 5′ m7G caps of rRNAs, the isoform diversity of 12S rRNA, the polycistronic transcripts and natural antisense transcripts of mitochondrial genes et al. These findings could challenge and enrich fundamental concepts of mitochondrial gene transcription and RNA processing, particularly of the rRNA primary (sequence) structure. The methodology constructed in this study can also be used to study gene expression or RNA processing of nuclear genomes.

本研究基于PacBio测序平台，以麻皮蝽（Erthesina fullo Thunberg）为实验材料，完成了首个全长昆虫转录组测序。我们构建了首份动物线粒体基因组定量转录图谱，并建立了一套简洁直观的方法学，用于探究线粒体基因转录、RNA加工、mRNA成熟及其他相关研究主题。本研究所得结果多数与既往研究相符，但据我们所知，部分发现为首次报道。本次新发现包括线粒体基因高水平表达、核糖体RNA（rRNA）的3′端多聚腺苷酸化及潜在的5′端7-甲基鸟苷（m7G）帽子结构、12S核糖体RNA的异构体多样性、线粒体基因的多顺反子转录本与天然反义转录本等。这些发现或将挑战并丰富线粒体基因转录与RNA加工的基础认知，尤其是核糖体RNA的一级（序列）结构相关理论。本研究构建的方法学亦可用于研究核基因组的基因表达与RNA加工过程。