What the egg can tell about its hen: Embryonic development on the basis of dynamic energy budgets
What the egg can tell about its hen: Embryonic development on the basis of dynamic energy budgets
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DOI：
10.1007/s00285-008-0195-x
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发表时间：
2009-03-01
影响因子：
1.9
通讯作者：
Kooijman, S. A. L. M.
中科院分区：
文献类型：
--
作者：
Kooijman, S. A. L. M.
后代的能量成本在将分配给繁殖的资源转换为后代数量以及从易于测量的数量中获得能量预算参数方面很重要。一个有效的数值计算程序，以获得此成本的动态能量预算理论的背景下，鸡蛋和胎儿，它规定，出生时发生的成熟度超过一个阈值和产妇的影响，确定在出生时的储备密度。本文将以前的工作扩展到任意值的成熟度和躯体的维护成本的比率。我讨论的相对大小和年龄在出生时的身体尺寸缩放的影响，并得出结论，出生时的大小，相反的出生时的年龄，协变的维护比。除了出生时成熟度的进化适应，这种协变可能解释一些观察到的出生时相对长度的分散。该理论可用于评估在例如胚胎发育的两细胞阶段中分离细胞的效果，以及去除初始卵块的效果。如果细胞分离几乎不影响能量参数，身体大小的比例关系意味着细胞分离只能成功地发生在物种足够大的最大体长（成年），即一些大型蚤的两倍。有毒化合物，增加成本的合成结构，减少分配到生殖间接通过生命周期，因为食物的吸收是与大小。然而，它们还可以减小卵子的大小，从而在低浓度下刺激繁殖率。目前的理论为这一众所周知的现象提供了一种可能的解释。
The energy cost of offspring is important in the conversion of resources allocated to reproduction to numbers of offspring, and in obtaining energy budget parameters from quantities that are easy to measure. An efficient numerical procedure is presented to obtain this cost for eggs and foetusses in the context of the dynamic energy budget theory, which specifies that birth occurs when maturity exceeds a threshold value and maternal effects determine the reserve density at birth. This paper extends previous work to arbitrary values of the ratio of the maturity and somatic maintenance costs. I discuss the body size scaling implications for the relative size and age at birth and conclude that the size at birth, contrary to the age at birth, covaries with the maintenance ratio. Apart from evolutionary adaptation of the maturity at birth, this covariation might explain some of the observed scatter in the relative length at birth. The theory can be used to evaluate the effects of the separation of cells in e.g. the two-cell stage of embryonic development, and of the removal of initial egg mass. If cell separation hardly affects energy parameters, body size scaling relationships imply that cell separation can only occur successfully in species with sufficiently large maximum body length (as adult); i.e. some two times that of Daphnia magna. Toxic compounds that increase the cost of synthesis of structure, decrease the allocation to reproduction indirectly via the life cycle, because food uptake is linked to size. They can also decrease the egg size, however, such that the reproduction rate is stimulated at low concentrations. The present theory offers a possible explanation for this well-known phenomenon.