Miller Dana L, Roth Mark B
Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Curr Biol. 2009 Jul 28;19(14):1233-7. doi: 10.1016/j.cub.2009.05.066. Epub 2009 Jul 2.
At least 100 mammalian species exhibit embryonic diapause, where fertilized embryos arrest development in utero until suitable seasonal or nutritional environments are encountered. Delaying maternal investments in producing offspring allows these animals to utilize limited resources to survive while searching for better conditions and ensures that progeny are not produced when they are unlikely to survive. In addition, embryos may be protected from external environmental vicissitudes while in utero. Here we demonstrate embryonic diapause in C. elegans, and show that this diapause protects embryos from otherwise lethal hypoxia. Diapausing embryos in utero require san-1 to survive, indicating that hypoxia-induced embryonic diapause may be mechanistically related to suspended animation. Furthermore, we show that neuronal HIF-1 activity in the adult dictates the O(2) tension at which embryonic diapause is engaged. We suggest that the maternal perception of hypoxia stimulates a response to protect embryos in utero by inducing diapause, a natural form of suspended animation. This response is likely to be an important strategy to improve offspring survival in harsh conditions and allow adults to find environments more suitable for reproductive success.
至少100种哺乳动物表现出胚胎滞育现象，即受精胚胎在子宫内停止发育，直至遇到适宜的季节或营养环境。推迟母体对后代的投入，使这些动物能够利用有限的资源生存，同时寻找更好的条件，并确保在后代不太可能存活时不进行繁殖。此外，胚胎在子宫内时可能会受到保护，免受外部环境变化的影响。在此，我们证明了秀丽隐杆线虫存在胚胎滞育现象，并表明这种滞育保护胚胎免受原本致命的低氧环境影响。子宫内处于滞育状态的胚胎需要san-1才能存活，这表明低氧诱导的胚胎滞育可能在机制上与假死有关。此外，我们还表明，成虫体内神经元的HIF-1活性决定了胚胎进入滞育状态时的氧气张力。我们认为，母体对低氧的感知通过诱导滞育（一种自然的假死形式）刺激一种反应，以保护子宫内的胚胎。这种反应可能是在恶劣条件下提高后代存活率并使成虫找到更适合繁殖成功的环境的重要策略。
