RNA-seq reveals extremely low levels of reticulocyte-derived globin gene transcripts in peripheral blood from cattle (Bos taurus)

RNA-seq has emerged as an important technology for measuring gene expression in peripheral blood samples collected from humans and other vertebrate species. However, an obstacle to these methods in many mammalian species is the presence of reticulocyte-derived globin mRNAs in large quantities, which can complicate RNA-seq library sequencing and impede detection of other mRNA transcripts. Here, we use comparative analyses of published RNA-seq data sets from human, porcine, and equine peripheral blood, in addition to bovine data generated by us, to systematically assess the impact of globin mRNA on routine transcriptome profiling of whole blood in cattle and horses. Bovine peripheral blood was collected into Tempus blood RNA tubes and total RNA was subsequent extracted. Ten paired-end 2 x 100 bp RNA-seq libraries were generated and then sequenced in an Illumina HiSeq 2000 platform over five lanes.The results of these analyses demonstrate that total RNA isolated from equine and bovine peripheral blood contains very low levels of globin mRNA transcripts, thereby negating the need for globin depletion and greatly simplifying blood-based transcriptomics studies in these two domestic species.