Research Paper Volume 3, Issue 2 pp 125—147

Figure 5. Lipid biosynthesis changes associated with C. elegans longevity. Black arrows in this schematic diagram indicate successive steps in fatty-acid biosynthesis by C. elegans, based on previously published data [24,25]. Enzyme activities (“+2C” for elongases, “Δn”, “n-3” or “n-6” for desaturases) and the implicated genes are indicated beside each arrow, in green font to indicate that transcripts encoding that enzyme are downregulated with increasing life span, or in red to show upregulation. Block arrows behind the names of fatty-acid classes are similarly color-coded, with the width of the arrow corresponding to the strength of the correlation to longevity. Lipids increase in melting temperature with increasing chain length and/or saturation level; thus shifts toward shorter chains with less desaturation, as seen in long-lived strains, may be neutral with respect to membrane fluidity.