(B ) The mean lifespan response of these worms shows lifespan extension for animals transferred on day 2 or later but a negative effect on lifespan for animals subjected to DR from day 1 of adulthood, possibly due to developmental effects.
The above-mentioned communication states that "there is increasingly wide acceptance of the link between animal welfare and animal health, and even, by extension, between animal welfare and food safety and food quality".
Studies in a mouse model of Huntington's disease show that reducing IRS2 level in brain induces lifespan extension of animals with improved mitochondrial function, autophagy, and oxidative stress resistance (Sadagurski et al., 2011), which is linked to increased nuclear localization of the transcription factor FOXO1 and expression of FOXO1-dependent genes that exert these beneficial effects.
DAF-16/FoxO also promotes life span extension in animals lacking a germline (Hsin and Kenyon 1999).
The lifespan extension for animals imparted by the sirtuins is up to 50% [ 3].
Collectively, these data suggest that both DAs and DAF-12 contribute to life span extension in animals with reduced DAF-2/InsR activity.
Therefore, although DAF-16F is dispensable for longevity in the presence of DAF-16A, it is required for life span extension in animals lacking DAF-16A.
Additionally, the lifespan extension of animals subjected to whole-life or adult-only pat-4/ILK RNAi is daf-16/FoxO-independent (Hansen et al., 2005; Curran & Ruvkun, 2007).
Because neither Δ- nor Δ-DA is detectable in daf-36 null mutants (Wollam et al. 2011), these results suggest that DAs are required for maximal life span extension in animals subjected to daf-2 RNAi.
The first genetic longevity studies mainly focused on lifespan regulating loci that emerged from animal models 22. Lifespan extension in animal models was obtained by applying caloric restriction or by modifying gene functions (mutagenesis) using RNA interference, knock-out or overexpression of single genes (GenAge; http://genomics.senescence.info/genes/) 23.
Extension to animal model genomic predictions (AMGP) is not straightforward, because most of the animals that are involved in the genetic evaluation are not genotyped.
