A Genome-Wide Longitudinal Transcriptome Analysis of the Aging Model Podospora anserine
Figure 6
Comparison of down-regulated genes in the grisea mutant and the wild type.
(a) Common down-regulated genes within the age-dependent transcriptome of the wild-type ‘s’ and the long-lived mutant grisea of P. anserina. 556 genes of the grisea transcriptome were identified to be down-regulated with a factor of at least 3 and a p-value of ≤0.01 for differential expression [22]. The 1,202 genes, identified as being down-regulated during aging in this study, have 89 genes in common. (b) 10,000 simulated experiments with two sets of randomly picked gene names, each set of the same size as the two sets (wild type, grisea), were applied. The box plot shows that the 89 common genes were extreme outliers. (c) The results of the random experiments are normally distributed with a mean of μ≈66.05 and a standard deviation of σ≈7.39. Our determined value of 89 is greater than three times sigma, indicating that the corresponding genes do not occur randomly. (d) All enriched GO terms in the set of the 89 common genes with a p-value ≤0.01 are depicted. Copper associated terms can be found on the very top. (e) Four genes already identified as putative target genes of transcription factor GRISEA are found within these 89 common genes. Due to its irregular expression profile, the gene, encoding the putative copper transporter PaCTR1, is not among the 89 common genes.