A comparison between ribo-minus RNA-sequencing and polyA-selected RNA-sequencing

To compare the two RNA-sequencing protocols, ribo-minus RNA-sequencing (rmRNA-seq) and polyA-selected RNA-sequencing (mRNA-seq), we acquired transcriptomic data–52 and 32 million alignable reads of 35 bases in length–from the mouse cerebrum, respectively. We found that a higher proportion, 44% and 25%, of the uniquely alignable rmRNA-seq reads, is in intergenic and intronic regions, respectively, as compared to 23% and 15% from the mRNA-seq dataset. Further analysis made an additional discovery of transcripts of protein-coding genes (such as Histone, Heg1, and Dux), ncRNAs, snoRNAs, snRNAs, and novel ncRNAs as well as repeat elements in rmRNA-seq dataset. This result suggests that rmRNA-seq method should detect more polyA- or bimorphic transcripts. Finally, through comparative analyses of gene expression profiles among multiple datasets, we demonstrated that different RNA sample preparations may result in significant variations in gene expression profiles.