For OregonR only, the highest food concentration caused egg laying to decrease, which indicated that the associated lifespan decrease from 1.5× to 2× was not accompanied by increased intake of biologically valuable nutrition and therefore could be due to a non-specific detrimental effect of high food.
However, whether autophagy plays similar roles in decreased metabolic signaling associated lifespan extension in vertebrates still needs to be clarified.
QTL and artificial selection experiments have demonstrated a highly complex genetic architecture, with many genetic correlations among lifespan and associated life history traits [e.g. 2], [3].
Analysis of variance (ANOVA) revealed six polymorphic markers significantly associated with lifespan, while no significant association with lifespan was seen for sex or marker by sex interaction.
Haplotypes composed of four makers, A433T, G871C, A1050G, and C1177T, three proximal markers adjacent to the structural gene, G871C, A1050G, and C1177T, and two markers with minimal P-values for individual association with lifespan, G871C and C1177T, were significantly associated with lifespan (Table 3, Table S1).
After determining which genetic markers were most strongly associated with lifespan, they applied that knowledge to DNA samples from another set of individuals.
Comparative genomics and linkage analysis identify candidate genes associated with lifespan differences between various turquoise killifish strains.
Increased proteolytic activities (autophagic and proteasomal [39, 40]) and the up-regulation of one or more heat shock and/or chaperone proteins are associated with lifespan extension in yeast [41], birds and mammals [42]; they help to maintain proteostasis by degrading altered proteins.
G871C and C1177T are the two polymorphic markers that form the haplotype that is significantly associated with lifespan.
A growing body of evidence indicates that restricted caloric intake is associated with lifespan extension and longevity in various organisms including yeast, worms, flies and even mammals [1] [5].
Since reduced mth expression is associated with lifespan extension [8], we predicted that the mthΔ6 and mth1 mutants would exhibit increased longevity relative to the mthR3 wild-type allele.
