Sf3b1 haploinsufficiency does not activate the NMD pathway. (A) A scatter diagram of microarray analysis. WT and Sf3b1^+/− LSK cells were isolated from 11-month-old WT and Sf3b1^+/− mice and recipient mice reconstituted with WT and Sf3b1^+/− BM cells at 9 months posttransplantation and then analyzed by microarray-based expression analysis. The average signal levels of Sf3b1^+/− cells compared with those of WT cells are plotted. The red and green lines represent the borderline for 2-fold increase and 2-fold decrease, respectively, and the numbers of genes altered by >2-fold are indicated. (B) The gene set enrichment analysis demonstrating a significant negative enrichment of the NMD pathway genes in Sf3b1^+/− LSK cells relative to WT LSK cells. Normalized enrichment scores (NSE), nominal P values, and false discovery rates (FDRs) are indicated. Red and blue represent positive (up-regulated in the given genotype relative to WT) and negative (up-regulated in WT relative to the given genotype) enrichment, respectively. Heat maps showing the gene expression profiles of 30 randomly selected genes are indicated below the plot.