Fig. 3.

DE transcripts enriched for intercalary heterochromatin and the 4th chromosome. (a) Positional information of differentially expressed genic transcripts across both strains. The notation “het” indicates that the genic location intersects with heterochromatin-associated proteins, H3K9me2/me3, as reported in Kharchenko et al. 2011. DE (differentially expressed) genes located in regions of intercalary heterochromatin are marginally enriched for significance (Chi-squared with Yate’s correction, two-tailed p-value <.0489) but do not show a directional change of expression with age. The 4th chromosome is highly enriched for DE genes considering its limited gene composition Chi-squared with Yate’s correction, two-tailed p-value < .0001. (b) Log2(young/old RPKM) of all genes located in heterochromatin versus Log2(young/old RPKM) genome-wide expression change with age. Genes in heterochromatin show similar age-related pattern of expression change as the rest of the genome