Figure 3. DNA replication, recombination, and repair genes are repressed during senescence. (A) Canonical pathway generated from the IPA analysis of the list of downregulated genes shows progressive changes of senescence-specific protein complexes associated with cell cycle control of chromosomal replication. Genes that are essential for pre-replication complex and initiation of DNA replication are decreased during senescence. Green denotes downregulated gene expression. (B) Expression levels of the genes RAD51, CDC6, and MCM6 were validated by RT-PCR in control, replicative senescence (RS) and TNF-α-induced senescence (TIS). GAPDH levels were used for normalization. Means ± SD are shown.