GSE124202
Comparing the m6A transcriptoms of Mettl14fl/fl and oligodendrocyre precursor cell (OPCs) and mature oligodendrocytes(OL) using m6A-SMART-seq
The goal of the experiment is to determine the m6A  tagged transcripts after the Mettl14 gene inactivation in OPCs and mature oligodendrocytes using Z score > 0 . Methods: mRNA from total RNA of  Mettl14fl/fl OPCs and mature oligodendrocytes was purified with Dynabeads Oligo (dT)25 (ThermoFisher; 61006). The equivalent amount of input and m6A-imunoprecipitated RNA were prepared for library generation using the SMART-seq protocol as described (Picelli et al., 2014). Three biological replicates of control OPCs and  three biological replicates of control oligodendrocytes were sequenced using Illumina NextSeq 500. Adapters were trimmed from original reads using Trimmomatic and low-quality reads were removed. The remaining reads were then mapped to the mouse genome (mm10) using STAR aligner (Dobin et al., 2013). To measure the relative m6A level per gene, the ratio of m6A IP/ Input was first calculated. The Z scores were then obtained by comparing the ratios (m6A IP/ Input) to the mean of the group to reflect the relative m6A level per gene on a transcriptome-wide scale. Results: The m6A-seq analyses detected 3554 m6A marked transcripts in OPCs and 2606 m6A marked transcripts in oligodendrocytes.There are 2806 transcripts with the m6A mark in OPCs that were present but not marked in oligodendrocytes , and 1626 transcripts that possessed the m6A mark in oligodendrocytes but not in OPCs . Only 23 of the shared transcripts , showed the m6A mark in both OPCs and oligodendrocytes. Conclusions: The dynamic nature of the m6A mark in oligodendrocyte lineage cells suggests that it may play an important role in oligodendrocyte differentiation and CNS myelination. Overall design: mRNA from total RNA of  Mettl14fl/fl OPCs and mature oligodendrocytes was purified , immunoprecipitaed with m6A antibody, and then sequenced using the SMART-seq protocol.