Department of Biology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina 27599.
Integr Comp Biol. 2003 Jul;43(3):450-8. doi: 10.1093/icb/43.3.450.
Functional challenges can differ among life-history stages, yet performance at one stage may be linked to the outcome of performance at others. For example, adult performance, in terms of the location or timing of reproduction in response to environmental signals, can set conditions that affect the performance of developmental stages. In marine invertebrates, however, early performance has been studied primarily in the laboratory. I outline an integrative approach to the study of field reproductive performance in a marine gastropod that undergoes development in intertidal habitats. Embryos within gelatinous masses experience high variability in development temperature and frequent exposure to thermal stress. In laboratory experiments, developmental performance was measured as a function of maximum temperature (T(max)) experienced during fluctuations that mimicked field tidal profiles. Performance curves showed declines that coincided with temperature thresholds for heat shock protein (Hsp) expression, a signal of cellular stress. Application of laboratory results to field records of T(max) predicted large variation in the survival of embryos deposited on different days. Timing of field reproduction was non-random with respect to T(max), suggesting that adults could help to buffer embryos from environmental stress. Embryo survival, however, was not predicted to benefit from the non-random pattern of adult reproduction. Adults may be constrained to respond to information that only weakly predicts conditions that embryos will experience. Studies that incorporate linkages between life cycle stages in the field may better reveal how performance capacities and constraints at one stage can influence performance and selection at others.
功能挑战可能因生活史阶段而异，但一个阶段的表现可能与其他阶段的表现结果相关。例如，成年期的表现，例如根据环境信号在何处或何时繁殖，可以设定影响发育阶段表现的条件。然而，在海洋无脊椎动物中，早期表现主要在实验室中进行了研究。我概述了一种综合方法来研究一种在潮间带栖息地发育的海洋腹足纲动物的野外生殖表现。在凝胶状物质中的胚胎经历了发育温度的高度变化和频繁暴露于热应激。在实验室实验中，将发育性能作为在模拟野外潮汐曲线的波动过程中经历的最高温度 (T(max)) 的函数来测量。性能曲线显示出下降，与热休克蛋白 (Hsp) 表达的温度阈值一致，这是细胞应激的信号。将实验室结果应用于 T(max) 的野外记录预测了在不同日期沉积的胚胎的存活率有很大差异。野外繁殖的时间与 T(max) 无关，这表明成年个体可以帮助胚胎免受环境压力。然而，胚胎的存活率并没有从成年个体繁殖的非随机模式中受益。成年个体可能受到限制，只能对仅微弱预测胚胎将经历的条件的信息做出反应。在野外将生命阶段之间的联系纳入研究的研究可能更好地揭示一个阶段的表现能力和约束如何影响其他阶段的表现和选择。
