BACKGROUND Animals with polyploid, hybrid nuclei offer a challenge for models of gene expression and regulation during embryogenesis. To understand how such organisms proceed through development, we examined the timing and prevalence of mortality among embryos of unisexual salamanders in the genus Ambystoma. RESULTS Our regional field surveys suggested that heightened rates of embryo mortality among unisexual salamanders begin in the earliest stages of embryogenesis. Although we expected elevated mortality after zygotic genome activation in the blastula stage, this is not what we found among embryos which we reared in the laboratory. Once embryos entered the first cleavage stage, we found no difference in mortality rates between unisexual salamanders and their bisexual hosts. Our results are consistent with previous studies showing high rates of unisexual mortality, but counter to reports that heightened embryo mortality continues throughout embryo development. CONCLUSIONS Possible causes of embryonic mortality in early embryogenesis suggested by our results include abnormal maternal loading of RNA during meiosis and barriers to insemination. The surprising survival rates of embryos post-cleavage invites further study of how genes are regulated during development in such polyploid hybrid organisms.

中文翻译：

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多倍体杂交sal胚胎的存活。

背景技术具有多倍体，杂种核的动物对胚胎发生过程中的基因表达和调控模型提出了挑战。为了了解此类生物如何通过发育进行，我们研究了Ambystoma属中单性sal的胚胎死亡的时间和普遍性。结果我们的区域性实地调查表明，单性sal的胚胎死亡率升高始于胚胎发生的最早阶段。尽管我们预期在胚泡阶段合子基因组激活后死亡率会升高，但这不是我们在实验室饲养的胚胎中发现的。一旦胚胎进入第一个分裂期，我们发现单性ise和双性恋宿主之间的死亡率没有差异。我们的结果与以前的研究表明单性死亡率高的研究结果一致，但是与报道的胚胎死亡率在整个胚胎发育过程中持续升高的报道相悖。结论我们的结果表明，早期胚胎发生中胚胎死亡的可能原因包括减数分裂期间母体RNA异常负载和授精障碍。卵裂后胚胎的惊人存活率引起人们对这种多倍体杂种生物发育过程中基因调控的进一步研究。