Does the respiratory rate in sea urchin embryos increase during early development without proliferation of mitochondria?

Dev Growth Differ. 1997 Apr;39(2):179-89. doi: 10.1046/j.1440-169x.1997.t01-1-00006.x.

Abstract

During early development of the sea urchin, the respiratory rate, enhanced upon fertilization, is maintained up to hatching (pre-hatching period) and then gradually increases to a maximum at the gastrula stage (post-gastrula period). Except for a short duration after fertilization, respiration in embryos is strongly inhibited by CN- and antimycin A. During the whole span of early development, the amounts of proteins, cytochromes and the specific activities of cytochrome c oxidase and reduced nicotinamide adenine dinucleotide (NADH) cytochrome c reductase in mitochondria are practically the same as in unfertilized eggs. A marked augmentation of mitochondrial respiration after hatching probably occurs without net increase in whole mitochondrial intrinsic capacities. Carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP) or tetramethyl p-phenylenediamine (TMPD) enhances the respiratory rate in the pre-hatching period but hardly augments the respiration in the post-gastrula period. In the presence of both FCCP and TMPD, the respiratory rate in the pre-hatching period was as high as in the post-gastrula period. Probably, electron transport in the mitochondrial respiratory chain is regulated by acceptor control and limitation of cytochrome c reduction in the pre-hatching period and released from those regulations in the post-gastrula period. Acceptor control of respiration is experimentally reproduced in isolated mitochondria by making adenine nucleotide levels as those levels in the pre-hatching period.

MeSH terms

  • Animals
  • Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / pharmacology
  • Centrifugation, Density Gradient
  • Chloramphenicol / pharmacology
  • Cyanides / pharmacology
  • Cycloheximide / pharmacology
  • Dactinomycin / pharmacology
  • Electron Transport
  • Electron Transport Complex IV / metabolism
  • Indicators and Reagents / pharmacology
  • Mitochondria / enzymology
  • Mitochondria / physiology*
  • NADH Dehydrogenase / metabolism
  • Oligomycins / pharmacology
  • Oxygen Consumption
  • Protein Synthesis Inhibitors / pharmacology
  • Sea Urchins / embryology*
  • Succinate Cytochrome c Oxidoreductase / metabolism
  • Tetramethylphenylenediamine / pharmacology
  • Uncoupling Agents / pharmacology

Substances

  • Cyanides
  • Indicators and Reagents
  • Oligomycins
  • Protein Synthesis Inhibitors
  • Uncoupling Agents
  • Dactinomycin
  • Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone
  • Chloramphenicol
  • Cycloheximide
  • Succinate Cytochrome c Oxidoreductase
  • NADH Dehydrogenase
  • Electron Transport Complex IV
  • Tetramethylphenylenediamine