Long-term survival of anoxia despite rapid ATP decline in embryos of the annual killifish Austrofundulus limnaeus.
نویسندگان
چکیده
Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence of oxygen. Survival of anoxia is associated with entry into a state of metabolic dormancy known as diapause. However, extreme tolerance of anoxia is retained for several days of post-diapause development. Rates of heat dissipation in diapause II and 4 days post-diapause II embryos were measured under aerobic conditions and during the transition into anoxia. Phosphorylated adenylate compounds were quantified in embryos during entry into anoxia and after 12 hr of aerobic recovery. Rates of heat dissipation were not affected by exposure to anoxia in diapause II embryos, while post-diapause II embryos experienced a profound decrease in heat dissipation. ATP decreased substantially in both developmental stages upon exposure to anoxia, and all indicators of cellular energetic status indicated energetic stress, at least based on the mammalian paradigm. The rate of decline in ATP is the most acute reported for any vertebrate. The mechanisms responsible for cellular survival despite a clear dysregulation between energy production and energy consumption remain to be identified. Necrotic and apoptotic cell death in response to hypoxia contribute to poor survival during many diseases and pathological conditions in mammals. Understanding the mechanisms that are in place to prevent maladaptive cell death in embryos of A. limnaeus may greatly improve treatment strategies in diseases that involve hypoxia and reperfusion injuries.
منابع مشابه
Avoidance of Apoptosis in Embryonic Cells of the Annual Killifish Austrofundulus limnaeus Exposed to Anoxia
Embryos of the annual killifish Austrofunduluslimnaeus have unequalled ability among vertebrates to survive long-term anoxia. Surprisingly, these embryos can survive for months in anoxia despite a large-scale decrease in ATP levels during the initial hours of anoxic exposure. These conditions are known to trigger apoptotic cell death in mammalian cells as a result of ischemia or anoxia. Anoxia-...
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The annual killifish Austrofundulus limnaeus inhabits ephemeral ponds in regions of Venezuela, South America. Permanent populations of A. limnaeus are maintained by production of stress-tolerant embryos that are able to persist in the desiccated sediment. Previous work has demonstrated that A. limnaeus have a remarkable ability to tolerate extended periods of anoxia and desiccating conditions. ...
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The annual killifish Austrofundulus limnaeus inhabits ephemeral ponds in regions of northern South America, where they survive the periodic drying of their habitat as diapausing embryos. These diapausing embryos are highly resistant to a number of environmental insults such as high temperature, dehydration, anoxia, and increased salinity. Molecular chaperones are known to play a role in stabili...
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عنوان ژورنال:
- Journal of experimental zoology. Part A, Ecological genetics and physiology
دوره 317 8 شماره
صفحات -
تاریخ انتشار 2012