Fetal origins of developmental plasticity: Are fetal cues reliable predictors of future nutritional environments?
Fetal origins of developmental plasticity: Are fetal cues reliable predictors of future nutritional environments?
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DOI：
10.1002/ajhb.20091
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发表时间：
2005-01-01
影响因子：
2.9
通讯作者：
Kuzawa, CW
中科院分区：
文献类型：
--
作者：
Kuzawa, CW
胎儿营养会引发广泛系统和健康结果的永久性调整的证据激发了人们对这些反应的进化意义的兴趣。本文从生命史理论和能量分配进化模型的角度评价胎儿发育可塑性的产后适应性意义。出生体重与多种代谢成本较高的产后功能呈正相关，这表明胎儿在面临营养挑战的环境时有能力分配能量不足的负担。降低总需求量可能会降低负能量平衡的风险，负能量平衡会严重影响对生存并非必需但对繁殖成功至关重要的功能。这些代谢调整的长期益处取决于胎儿是否能够获得预测其未来营养环境的线索，而对于长寿物种来说，由于季节性等短期生态波动，这个问题变得更加复杂。审查的证据表明，到达胎儿的营养物质流提供了近代母系祖先所经历的营养的综合信号，这有效地限制了任何特定怀孕期间对短期生态波动的反应。胎儿营养的这种能力可以最大限度地减少对短暂生态波动的生长反应，这里被定义为代际“表型惯性”，并被假设允许胎儿穿越季节性或其他随机影响的“噪音”，以读取长期生态趋势的“信号”。作为一种适应模式，表型惰性可以帮助生物体应对生态趋势，这些趋势太缓慢而无法被传统的发育可塑性追踪，但又太快而无法被自然选择追踪。从应用的角度来看，如果像胎儿生长这样的特征旨在通过整合代际信息来最大限度地减少短期波动的影响，那么公共卫生干预措施如果不关注个人而是关注母系，可能会最有效。 (C) 2004 Wiley-Liss, Inc.
Evidence that fetal nutrition triggers permanent adjustments in a wide range of systems and health outcomes is stimulating interest in the evolutionary significance of these responses. This review evaluates the postnatal adaptive significance of fetal developmental plasticity from the perspective of life history theory and evolutionary models of energy partitioning. Birthweight is positively related to multiple metabolically costly postnatal functions, suggesting that the fetus has the capacity to distribute the burden of energy insufficiency when faced with a nutritionally challenging environment. Lowering total requirements may reduce the risk of negative energy balance, which disproportionately impacts functions that are not essential for survival but that are crucial for reproductive success. The long-term benefit of these metabolic adjustments is contingent upon the fetus having access to a cue that is predictive of its future nutritional environment, a problem complicated in a long-lived species by short-term ecologic fluctuations like seasonality. Evidence is reviewed suggesting that the flow of nutrients reaching the fetus provides an integrated signal of nutrition as experienced by recent matrilineal ancestors, which effectively limits the responsiveness to short-term ecologic fluctuations during any given pregnancy. This capacity for fetal nutrition to minimize the growth response to transient ecologic fluctuations is defined here as intergenerational "phenotypic inertia," and is hypothesized to allow the fetus to cut through the "noise" of seasonal or other stochastic influences to read the "signal" of longer-term ecologic trends. As a mode of adaptation, phenotypic inertia may help the organism cope with ecologic trends too gradual to be tracked by conventional developmental plasticity, but too rapid to be tracked by natural selection. From an applied perspective, if a trait like fetal growth is designed to minimize the effects of short-term fluctuations by integrating information across generations, public health interventions may be most effective if focused not on the individual but on the matriline. (C) 2004 Wiley-Liss, Inc.