A mechanistic understanding of ageing revealed by studying the young

作者：Crespi Erica J^*

来源：Molecular Ecology, 2012, 21(6): 1307-1310.

DOI：10.1111/j.1365-294X.2011.05430.x

• antagonistic pleiotropy
• catch-up growth
• developmental plasticity
• oxidative stress
• telomere loss

A main focus within biomedical research is to understand how adverse environmental conditions experienced during early development affects lifelong health (Barker 1992). Within this context, extensive research in rodent models and humans has shown that intrauterine growth retardation (IUGR) caused by nutrient restriction during early development is often followed by post-natal catch-up growth when access to food resources improves. However, this accelerated growth rate seems to come at a cost, as metabolic and endocrine processes that are programmed during this time cause later-life onset of diseases such as obesity, insulin resistance and cardiovascular disease (reviewed in Crespi %26 Denver 2005). In this issue Molecular Ecology, Geiger (2012) asked what are the costs of catch-up growth in nutrient-restricted king penguin chicks (Fig.similar to 1) by measuring lengths of telomeres, the protective DNA sequences at the end of chromosomes, before and after catch-up growth, as the amount and rate of telomere sequence loss over time has been associated with reduced lifespan in both model and nonmodel organisms (see reviews of Costantini 2010; Haussmann %26 Marchetto 2010). Geiger (2011) found that chicks entering the post-winter growth season at a smaller size exhibited increased growth rates (i.e. catch-up growth) at the cost of increased oxidative stress and reduced telomere lengths compared with the chicks entering the growth period at a larger size. Furthermore, chicks that did not survive had drastically shorter telomere lengths and reduced antioxidant capacities at the beginning of the growth period than all other chicks, thereby directly associating telomere length to mortality. These results suggest that while catch-up growth allows smaller chicks to head off into the world on equal footing with chicks that hatched at a larger size, it likely comes at the cost of a shortened lifespan. Thus, this study provides a mechanism that supports the antagonistic pleiotropy theory of senescence (Promislow 2004).

• 出版日期2012-3