microRNA-196 regulates vertebral number and identity across species

Purpose: In this study, we identify global transcriptome alterations following removal of individual or multiple miR-196 family members in mouse. Next generation sequencing-derived transcriptome profiling (RNA-seq) was performed. Methods: A GFP reporter cassette was engineered to replace the mature miR-196a1 and miR-196a2 miRNA genomic loci in mouse (creating a knockout). GFP positive cells from an extensive knock-out allellic series of the three individual miR-196 genes, as detailed below, were isolated from E9.5 mouse embryos by FACS. miR-196b knockout cells were not marked with a fluorescent reporter and an assumption of co-expression with miR-196a2 was made. mRNA profiles were generated by deep sequencing in a minimum of four biological replicates per genotype, using an Illumina HiSeq 2000 instrument. Read information was mapped to the mouse genome and processed as described. Conclusions: Our study represents the first detailed analysis of embryonic transcriptomes following loss of single and multiple miR-196 family members. We identify complex dysregulation of many Hox genes, in addition to key developmental signalling pathways involved in somitogenesis. mRNA profiles of E9.5 mouse embryos with miR-196 loss-of-function were generated by deep sequencing, in a minimum of four biological replicates, using Illumina HiSeq 2000.