Although the experimental design is somewhat different, it appears that the median lifespan observed here is somewhat shorter than in medaka studies performed by Egami and coworkers in the 1960s and 1970s [17], which were conducted in an outdoor environment.
The declines with increasing lifespan, seen here for Δ6 and ω-3 desaturases (Table 2), support that interpretation.
North south differences regarding lifespan are here reported, thus further supporting the view that there is plenty of phenotypic variation in D. americana.
However, the 11% increase in lifespan observed here in B6 IGF-1R+/− females was markedly smaller than the 33% increase previously found in 129S2 females (Holzenberger et al., 2003).
We conclude that the elongation of lifespan observed here is not caused by respiratory deficiency and is independent of the retrograde response as defined by Jazwinski [ 14] and Butow [ 15].
To further assess the effect of p53 on mean, median, and "maximal lifespan" (defined operationally here as the 90th percentile of life span), 95% double bootstrap-t confidence intervals for the ratio of the means (or ratio of the percentiles) of the experimental and control samples were computed using a custom Fortran script.
In addition to extending lifespan as shown here, RNAi knockdown of the class I HDAC hda-3 was shown to protect against polyglutamine-mediated toxicity in a C. elegans Huntington's disease, while knockdown of most other HDACs increased toxicity [ 95].
Our subsequent projects in honey bees will focus on using pharmacological agents to explore whether there is a SIRT1-dependence for the lifespan and neurophysiological effects noted here.
Here, we measure lifespan variability by s x, the standard deviation of the age at death, conditional on survival to the index age x. Figure 1 shows that the standard deviation among newborn individuals, measured relative to its initial value, has declined since 1900, as has the variation in the distributions of ages at death conditional on survival to age 10.
