Skip to main content

Table 1 Biological classes of probe sets with an age effect on transcription levels in young and old mouse muscle.

From: Gene expression profiling of aging reveals activation of a p53-mediated transcriptional program

  # transcripts with age effect P-value  
Biological Process ↓Old ↑Old ↓Old ↑Old Ave. % CR Prevention
lipid metabolism (4.5%) 19 13 <0.0005 NS 101 ± 9
protein metabolism (16.3%) 55 61 NS NS 88 ± 5
carbohydrate metabolism (2.7%) 12 7 <0.05 NS 91 ± 15
energy pathways (1.7%) 10 2 <<0.0005 NS 100 ± 20
stress response (5.2%) 13 24 NS <0.05 90 ± 8
immune response (3.4%) 4 20 NS <0.005 99 ± 10
apoptosis (3.7%) 5 21 NS <<0.0005 62 ± 15
cell cycle (5.2%) 9 28 NS <0.005 66 ± 8
cell adhesion (4.1%) 18 11 <0.05 NS 49 ± 14
cytoskeleton organization and biogenesis (3.9%) 10 18 NS <0.005 102 ± 12
  1. Given in the above table are some of the more predominate biological processes, as determined by Gene Ontology [59], represented in the probe sets considered differentially expressed (PP > .90) in young and old mouse skeletal muscle. The number in parentheses is the percent each biological class represents out of all probe sets shown to have an age effect (712 total probe sets). Because genes can have multiple functions, many probe sets are associated with more than one biological process. Listed in the two middle columns on the left are the number of transcripts whose expression either decreased (↓ Old) or increased (↑ Old) in older mouse muscle. The middle columns on the right give the probability of obtaining the given transcript numbers for each biological class by chance. The last column gives the average CR prevention ± SE for all of the probe sets associated with these biological classes. The % CR prevention was calculated for each gene in the following manner: 100 × (old expression levels - CR expression levels)/(old expression levels - young expression levels). NS = not significant.