Fig. 4

Characteristics of aging-related lipidome changes. a Correlation between concentrations of aging-related lipids and expression of their interacting genes during the adult stage. The red dot shows the median absolute Spearman correlation coefficients (ρ). The gray box shows the background distribution of absolute ρ medians calculated by permutations of age labels 100 times. b Age distribution of transition points of the lipid concentration profiles during the adult stage. The y-axis shows the number of transition within a given age interval minus the background calculated by permutations of age labels 100 times. Light yellow dash lines show the age of transition points for fat mass (FM), fat-free mass (FFM), physical activity level (PAL), daily (DEE), basal (BEE) and activity energy expenditure (AEE) measurements from 529 individuals [58]. c The heatmap based on (1−ρ) distances among 682 aging-related lipids calculated using their concentrations across 178 samples from 174 adult individuals. Black boxes and labels show five clusters. d Temporal patterns of lipid concentrations in the five clusters. Cluster names and lipid numbers are shown on top. Each dot represents the average relative lipid concentration within a sample. The lines represent spline curves built with five degrees of freedom. The vertical dash lines show the modes of the transition point distribution. e Lipid classes enriched in the five clusters. Each dot represents the enrichment of a lipid class, with the size proportional to the number of overlapping lipids (red—significant enrichment; gray—not significant). The vertical dash lines indicate OR = 1. The horizontal dash lines indicate BH-corrected P = 0.05 of one-sided Fisher’s exact test. IPR isoprenoids, PPR polyprenols, PG glycerophosphoglycerols, PA glycerophosphates. f KEGG pathways enriched in the five clusters. Colors show the BH-corrected P values of hypergeometric tests