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Extreme anoxia tolerance in a vertebrate embryo
Author(s) -
Podrabsky Jason E.,
Lopez James,
Higashi Richard,
Fan Teresa,
Somero George N.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a827-b
Subject(s) - diapause , embryo , biology , embryogenesis , killifish , microbiology and biotechnology , andrology , botany , larva , fish <actinopterygii> , fishery , medicine
Embryos of the annual killifish Austrofundulus limnaeus can enter a state of reversible metabolic arrest when exposed to anoxia. This state of anoxia‐induced quiescence is distinct from entry into embryonic diapause that is part of this species’ natural development. Anoxia tolerance is gradually gained during early development and reaches extreme levels during diapause II when embryos can survive for over 90 days without oxygen at 25°C. Anoxia tolerance is gradually lost during post‐diapause II development. However, embryos that have broken diapause II and are actively developing remain highly tolerant of anoxia for several days. Metabolomics analysis of these embryos indicates that anoxia tolerance is inversely related to the rate of lactate accumulation during anoxia, even though all embryos accumulate mM quantities of lactate. Embryos that survive for extended periods of time accumulate up to 10 mM gamma‐aminobutyrate (GABA) and moderate amounts of succinate and alanine. The accumulation of high amounts of GABA may indicate that a mechanism for alleviating acidosis and/or protection of neurons from depolarization during anoxia is key to the survival of these embryos.