FAM13B knockdown in iCMs

Common human genetic variation near the FAM13B gene are associated with atrial fibrillation as well as with the expression level of FAM13B mRNA in human left atrial appendage tissues. To determine the effects of FAM13B gene expression in human cardiomyocytes derived from induced pluripotent stem cells (iCMs from iCell Cardiomyocytes), we used siRNA targeted against FAM13B to knockdown its gene expression (KD) or an siRNA with a scrambled sequence (SCR). Total RNA was prepared from biological triplicate plates of cells and subjected to bulk RNAseq. 100-bp paired-end sequencing was performed on the Illumina HiSeq 2000. The sequence reads were mapped to the human genome using the STAR aligner (version 2.3.0) to derive a digital count of the expression of genes, which were defined using the Ensembl gene catalog (version 69). Genes were filtered to ensure a CPM (counts per million) > 5 in at least 2 samples, resulting in 11,017 genes. Differential expression analyses of FAM13B KD versus control SCR siRNA in iCMs was performed using the limma-voom approach with false discovery rate control. 3 biological replicates each for FAM13B KD and scrambled siRNA control