Oxygen
consumption in unfertilized salmonid eggs: an indicator of egg quality?
M.
Holcomb, J.G. Cloud, J. Woolsey, R.L. Ingermann-2004
Comparative Biochemistry and Physiology part A: Molecular & Integrative
Physiology, 138(3): 349-354
Abstract:
A
negative correlation between oxygen consumption and fertility was observed
in both steelhead and chinook salmon eggs. However, this relationship was
attributed to bacterial growth. Elimination of samples with bacterial growth
resulted in no significant relationship between the rate of oxygen
consumption (VO2) and fertility. VO2 of unfertilized
eggs of both steelhead and chinook salmon was measured over a storage period
of up to 24 days (d). Despite declines in fertility during storage, VO2
did not significantly change throughout storage. The average respiration
rate for steelhead eggs was 3.4 nmol O2 per egg per h, and was
4.3 nmol O2 per egg per h for chinook salmon eggs. Treatment of
chinook salmon eggs with uncouplers of mitochondrial respiration,
2,4-dinitrophenol (2,4-DNP) and carbonyl cyanide
4-trifluoro-methoxyphenylhydrazone (FCCP), resulted in an increase in VO2
to 12.9 and 11.5 nmol O2 per egg per h, respectively. Treatment
with the putative uncoupler, clove oil, resulted in no change in VO2,
while KCN, an inhibitor of oxidative phosphorylation, reduced oxygen
consumption to zero. Copper caused an increase in oxygen consumption, even
in the absence of eggs, suggesting a need for caution in interpreting
changes in respiration rates as a result of metal exposure. Thus,
unfertilized salmonid eggs demonstrated submaximal VO2, which was
not correlated with fertility.
(Department
of Biological Sciences and Center for Reproductive Biology, University of
Idaho, Box 443051, Moscow, ID 83844-3051, USA, e-mail of R.L. Ingermann: rolfi@uidaho.edu)