Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8, Canada.
J Comp Physiol B. 2013 Aug;183(6):821-31. doi: 10.1007/s00360-013-0751-6. Epub 2013 Mar 28.
The effects of early environmental conditions can profoundly affect individual development and adult phenotype. In birds, limiting resources can affect growth as nestlings, but also fitness and survival as adults. Following periods of food restriction, individuals may accelerate development, undergoing a period of rapid "catch-up" growth, in an attempt to reach the appropriate size at adulthood. Previous studies of altricial birds have shown that catch-up growth can have negative consequences in adulthood, although this has not been explored in species with different developmental strategies. Here, we investigated the effects of resource limitation and the subsequent period of catch-up growth, on the morphological and metabolic phenotype of adult Japanese quail (Coturnix japonica), a species with a precocial developmental strategy. Because males and females differ in adult body size, we also test whether food restriction had sex-specific effects. Birds that underwent food restriction early in development had muscles of similar size and functional maturity, but lower adult body mass than controls. There was no evidence of sex-specific sensitivity of food restriction on adult body mass; however, there was evidence for body size. Females fed ad lib were larger than males fed ad lib, while females subjected to food restriction were of similar size to males. Adults that had previously experienced food restriction did not have an elevated metabolic rate, suggesting that in contrast to altricial nestlings, there was no metabolic carry-over effect of catch-up growth into adulthood. While Japanese quail can undergo accelerated growth after re-feeding, timing of food restriction may be important to adult size, particularly in females. However, greater developmental flexibility compared to altricial birds may contribute to the lack of metabolic carryover effects at adulthood.
早期环境条件的影响可以深刻地影响个体的发育和成年表型。在鸟类中，作为雏鸟，资源限制会影响生长，但作为成鸟，也会影响适应度和生存。在经历食物限制后，个体可能会加速发育，经历一段快速的“追赶”生长，以试图达到成年时的适当大小。先前对早成性鸟类的研究表明，追赶生长在成年后可能会产生负面影响，尽管这在具有不同发育策略的物种中尚未得到探索。在这里，我们研究了资源限制及其随后的追赶生长期对成年日本鹌鹑（Coturnix japonica）形态和代谢表型的影响，日本鹌鹑是一种具有早熟发育策略的物种。因为雄性和雌性在成年体型上存在差异，我们还测试了食物限制是否对成年体型具有性别特异性影响。在早期发育中经历食物限制的鸟类，其肌肉大小和功能成熟度相似，但成年体重比对照组低。没有证据表明食物限制对成年体重具有性别特异性敏感性；然而，有证据表明存在体型差异。自由采食的雌性比自由采食的雄性体型大，而经历食物限制的雌性与雄性体型相似。以前经历过食物限制的成鸟没有升高的代谢率，这表明与早成性雏鸟不同，追赶生长没有对成年代谢产生延续效应。尽管日本鹌鹑在重新喂养后可以经历加速生长，但食物限制的时间可能对成年体型很重要，特别是对雌性。然而，与早成性鸟类相比，更大的发育灵活性可能导致成年时缺乏代谢延续效应。
