Cell cycle-related genes. (A) Hierarchical clustering of differentially expressed cell cycle-related genes in PM, MY, and bm-PMN populations. The mean relative expression levels for genes in BM populations are presented by a color scale, whereby red reflects a high expression (3 × SD), white reflects mean expression, and blue reflects low expression level (-3 × SD). (B) Representative flow cytometry analysis of G₁, S, G₂/M phases in PM, MY, bm-PMN populations. Cells to the left of the G₁ population with less than 2n DNA content are undergoing apoptosis.