Embryonic development is of great importance because it determines congenital anomalies and influences their severity. However, little is known about the actual probabilities of success or failure and about the nature of early embryonic defects. Here, we propose that the analysis of embryonic mortality as a function of post-fertilization time provides a simple way to identify major defects. By reviewing the literature, we show that even small initial defects, e.g., spatial cellular asymmetries or irregularities in the timing of development, carry with them lethal effects in subsequent stages of embryogenesis. Although initially motivated by human study, in this contribution, we review the few embryonic mortality data available for farm animals and highlight zebrafish as a particularly suited organism for such a kind of study because embryogenesis can be followed from its very beginning and observed easily thanks to eggshell transparency. In line with the few other farm animals for which data are available, we provide empirical evidence that embryonic mortality in zebrafish has a prominent peak shortly after fertilization. Indeed, we show how subsequent mortality rates decay according to a power law, supporting the role of the early embryonic mortality peak as a screening process rapidly removing defective embryos.

中文翻译：

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早期胚胎死亡率峰值的大小和意义

胚胎发育非常重要，因为它决定先天异常并影响其严重程度。然而，人们对成功或失败的实际概率以及早期胚胎缺陷的性质知之甚少。在这里，我们建议将胚胎死亡率作为受精后时间的函数进行分析，提供了一种识别主要缺陷的简单方法。通过回顾文献，我们发现即使是很小的初始缺陷，例如空间细胞不对称或发育时间不规则，也会在胚胎发生的后续阶段产生致命影响。尽管最初是出于人类研究的动机，但在这篇文章中，我们回顾了农场动物可用的少数胚胎死亡率数据，并强调斑马鱼是特别适合此类研究的生物体，因为胚胎发生可以从一开始就被跟踪并很容易观察到，这要归功于蛋壳透明度。与其他少数有可用数据的农场动物一样，我们提供的经验证据表明，斑马鱼的胚胎死亡率在受精后不久出现一个显着的峰值。事实上，我们展示了随后的死亡率如何根据幂律衰减，支持早期胚胎死亡率峰值作为快速去除缺陷胚胎的筛选过程的作用。