Hormone-mediated maternal effects in birds:: mechanisms matter but what do we know of them?
Hormone-mediated maternal effects in birds:: mechanisms matter but what do we know of them?
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DOI：
10.1098/rstb.2007.0007
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发表时间：
2008-05-12
影响因子：
6.3
通讯作者：
Schwabl, Hubert
中科院分区：
文献类型：
--
作者：
Groothuis, Ton. G. G.;Schwabl, Hubert
在过去的十年中，鸟类已被证明是很好的模型，研究在进化框架下的雌激素介导的母体效应。几乎所有这些研究都集中在母体类固醇激素对后代发育的作用，但缺乏对潜在机制的了解阻碍了进一步的进展。我们讨论了有关这些机制的几个假设，指出它们的生态和进化解释的相关性，并审查相关数据。我们首先研究母体激素是否可以在卵子中积累，而不依赖于母体循环中激素浓度的变化。这是重要的达尔文选择和女性的生理权衡，并在鸡蛋中的激素积累，这可能是不同的激素可能的机制，进行了审查。虽然血浆和卵黄中激素浓度的独立调节是可以想象的，但卵巢激素的数据还不确定。接下来，我们讨论胚胎对母体类固醇的利用，因为胚胎中的酶和受体系统可能与母亲的母体效应机制共同进化。我们认为剂量反应关系和雄激素的作用途径，并认为这些考虑可能有助于解释明显缺乏干扰母体类固醇性分化。最后，我们讨论了机制的多效性行动的母亲类固醇，因为连锁效应可能会影响父母和后代性状的共同进化，由于他们的作用，在调解的生理权衡。可能的机制是与胚胎中其他激素系统的相互作用。我们敦促内分泌学家着手建议机制的研究和行为生态学家调整他们的解释，以适应目前的知识机制。
Over the past decade, birds have proven to be excellent models to study hormone-mediated maternal effects in an evolutionary framework. Almost all these studies focus on the function of maternal steroid hormones for offspring development, but lack of knowledge about the underlying mechanisms hampers further progress. We discuss several hypotheses concerning these mechanisms, point out their relevance for ecological and evolutionary interpretations, and review the relevant data. We first examine whether maternal hormones can accumulate in the egg independently of changes in hormone concentrations in the maternal circulation. This is important for Darwinian selection and female physiological trade-offs, and possible mechanisms for hormone accumulation in the egg, which may differ among hormones, are reviewed. Although independent regulation of plasma and yolk concentrations of hormones is conceivable, the data are as yet inconclusive for ovarian hormones. Next, we discuss embryonic utilization of maternal steroids, since enzyme and receptor systems in the embryo may have coevolved with maternal effect mechanisms in the mother. We consider dose response relationships and action pathways of androgens and argue that these considerations may help to explain the apparent lack of interference of maternal steroids with sexual differentiation. Finally, we discuss mechanisms underlying the pleiotropic actions of maternal steroids, since linked effects may influence the coevolution of parent and offspring traits, owing to their role in the mediation of physiological trade-offs. Possible mechanisms here are interactions with other hormonal systems in the embryo. We urge endocrinologists to embark on suggested mechanistic studies and behavioural ecologists to adjust their interpretations to accommodate the current knowledge of mechanisms.