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Bioenergetic profiles of isolated mitochondria from diapausing embryos of the annual killifish Austrofundulus limnaeus
Author(s) -
Duerr Jeffrey M,
Podrabsky Jason E
Publication year - 2008
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.22.1_supplement.757.29
Subject(s) - diapause , killifish , biology , embryo , bioenergetics , mitochondrion , oxygen , larva , botany , biochemistry , chemistry , microbiology and biotechnology , fish <actinopterygii> , fishery , organic chemistry
The annual killifish, Austrofundulus limnaeus, occupy ephemeral pond habitats by producing diapausing embryos which can reduce their oxygen consumption rate by up 90% compared to developing embryos. Mitochondria isolated from whole embryos collected at 10 dpf, diapause II, post‐diapause, diapause III, post‐hatch larvae, and adult liver exhibited oxygen consumption rates that increased with developmental stage in the presence of glutamate or succinate. Measurements of electron transport chain activity reflected life‐stage specific regulation. Minimum ETC activity was observed during diapause II: complex I activity was 12% of adult, complex II was 25% of adult, and complex IV activity was 20% of adult. Proton leak was significantly greater during diapause III and elevated in diapause II and larvae relative to 10 dpf and adult in the presence of glutamate, whereas no significant difference in life stage‐specific proton leak was observed in the presence of succinate. P:O ratios in the presence of glutamate or pyruvate and succinate were between 2 and 2.5 and between 1 and 1.2 respectively for diapause III embryos and adults. Overall, these data agree with whole‐embryo oxygen consumption rates previously measured and suggest a coordinated suppression of the mitochondrial electron transport chain and oxidative capacity during diapause. Supported by NSF grant IBN‐0344578 to JEP.