Department of Biology, Portland State University, Portland, Oregon.
Health, Human Performance, and Athletics Department, Linfield University, McMinnville, Oregon.
Physiol Genomics. 2020 Sep 1;52(9):408-422. doi: 10.1152/physiolgenomics.00072.2020. Epub 2020 Aug 10.
The annual killifish, , survives in ephemeral ponds in the coastal deserts of Venezuela. Persistence through the dry season is dependent on drought-resistant eggs embedded in the pond sediments during the rainy season. The ability of these embryos to enter drastic metabolic dormancy (diapause) during normal development enables to survive conditions lethal to most other aquatic vertebrates; critical to the survival of the species is the ability of embryos to survive months and perhaps years without access to liquid water. Little is known about the molecular mechanisms that aid in survival of the dry season. This study aims to gain insight into the mechanisms facilitating survival of dehydration stress due to aerial exposure by examining metabolite profiles of dormant and developing embryos. There is strong evidence for unique metabolic profiles based on developmental stage and length of aerial exposure. Actively developing embryos exhibit more robust changes; however, dormant embryos respond in an active manner and significantly alter their metabolic profile. A number of metabolites accumulate in aerial-exposed embryos that may play an important role in survival, including the identification of known antioxidants and neuroprotectants. In addition, a number of unique metabolites not yet discussed in the dehydration literature are identified, such as lanthionine and 2-hydroxyglutarate. Despite high oxygen availability, embryos accumulate the anaerobic end product lactate. This paper offers an overview of the metabolic changes occurring that may support embryonic survival during dehydration stress due to aerial incubation, which can be functionally tested using genetic and pharmacological approaches.
年度弹涂鱼 生活在委内瑞拉沿海沙漠的季节性池塘中。在旱季的生存依赖于雨季时嵌入池塘沉积物中的抗干旱卵。这些胚胎在正常发育过程中进入剧烈代谢休眠（滞育）的能力使 能够在对大多数其他水生脊椎动物致命的条件下生存；对该物种的生存至关重要的是，胚胎能够在数月甚至数年没有接触到液态水的情况下存活。人们对有助于旱季生存的分子机制知之甚少。本研究旨在通过检查休眠和发育胚胎的代谢物谱，深入了解有助于因暴露于空气中而脱水应激的生存机制。有强有力的证据表明，基于发育阶段和暴露于空气中的时间长短，存在独特的代谢特征。活跃发育的胚胎表现出更剧烈的变化；然而，休眠的胚胎以积极的方式做出反应，并显著改变其代谢特征。在暴露于空气中的胚胎中积累了许多可能在生存中起重要作用的代谢物，包括鉴定出的已知抗氧化剂和神经保护剂。此外，还鉴定出了一些在脱水文献中尚未讨论过的独特代谢物，如硫代赖氨酸和 2-羟基戊二酸。尽管氧气供应充足，但胚胎仍会积累厌氧终产物乳酸盐。本文概述了可能支持胚胎在因空气孵化而导致的脱水应激期间生存的代谢变化，这些变化可以通过遗传和药理学方法进行功能测试。
