Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
J Gerontol A Biol Sci Med Sci. 2013 Apr;68(4):349-58. doi: 10.1093/gerona/gls170. Epub 2012 Aug 17.
We measured life span and fecundity of three reproductive modes in a clone of the monogonont rotifer Brachionus manjavacas subjected to chronic caloric restriction (CCR) over a range of food concentrations or to intermittent fasting (IF). IF increased life span 50%-70% for all three modes, whereas CCR increased life span of asexual females derived from sexually or asexually produced eggs, but not that of sexual females. The main effect of CR on both asexual modes was to delay death at young ages, rather than to prevent death at middle ages or to greatly extend maximum life span; in contrast CR in sexual females greatly increased the life span of a few long-lived individuals. Lifetime fecundity did not decrease with CCR, suggesting a lack of resource allocation trade-off between somatic maintenance and reproduction. Multiple outcomes for a clonal lineage indicate that different responses are established through epigenetic programming, whereas differences in life-span allocations suggest that multiple genetic mechanisms mediate life-span extension.
我们测量了慢性热量限制(CCR)下或间歇性禁食(IF)下三种繁殖模式的寿命和繁殖力在单腕轮虫 Brachionus manjavacas 克隆中的变化。IF 使所有三种模式的寿命延长了 50%-70%,而 CCR 则延长了有性或无性卵产生的雌性孤雌生殖的寿命,但不延长有性雌性的寿命。CR 对两种孤雌生殖模式的主要影响是延缓幼年期的死亡,而不是防止中年期的死亡或大大延长最大寿命;相比之下,CR 使少数长寿个体的雌性寿命大大延长。CCR 并没有降低终生繁殖力,这表明在躯体维持和繁殖之间不存在资源分配的权衡。克隆谱系的多种结果表明,不同的反应是通过表观遗传编程建立的,而寿命分配的差异表明,多种遗传机制介导了寿命的延长。