Related Experiment Video
Updated: Jun 19, 2026
08:10
Measurement of Oxygen Consumption Rates in Intact Caenorhabditis elegans
Published on: February 23, 2019
ON THE RATE OF OXYGEN CONSUMPTION BY FERTILIZED AND UNFERTILIZED EGGS : V. COMPARISONS AND INTERPRETATION
1Laboratory of General Physiology, Harvard University, Cambridge, the Department of Zoology, Columbia University, New York, and the Marine Biological Laboratory, Woods Hole.
The Journal of General Physiology
|October 30, 2009
Summary
Fertilization does not always increase oxygen consumption rates in eggs; instead, rates often converge to a similar level post-fertilization. This challenges the idea that increased oxidation is essential for initiating development.
Area of Science:
- Cellular Respiration
- Developmental Biology
- Reproductive Physiology
Background:
- Unfertilized eggs exhibit a wide range of oxygen consumption rates, varying significantly across species.
- Fertilization triggers changes in oxygen consumption, but these changes differ in direction and magnitude.
- Previous hypotheses suggested increased oxidation is the primary driver of fertilization and development initiation.
Purpose of the Study:
- To investigate the relationship between oxygen consumption rates and fertilization across diverse egg species.
- To determine if increased oxygen consumption is a necessary or universal feature of fertilization.
- To re-evaluate the role of oxidation in the initiation of embryonic development.
Main Methods:
- Measured absolute rates of oxygen consumption in unfertilized and fertilized eggs of various invertebrate species (e.g., Chaetopterus, Cumingia, Nereis, sea urchin).
- Compared oxygen consumption rates across different species and developmental stages.
- Analyzed the relationship between oxygen consumption changes and the onset of development.
Main Results:
- Oxygen consumption rates in unfertilized eggs vary widely (0.4–3.1 mm³ O₂/hr/10 mm³), while fertilized eggs show convergence (1.3–2.0 mm³ O₂/hr/10 mm³).
- Fertilization can decrease oxygen consumption (e.g., Chaetopterus, Cumingia) or increase it, depending on the species.
- The changes in oxygen consumption at fertilization appear to normalize rates across species, aligning with normally growing cells.
Conclusions:
- Increased oxygen consumption is not universally essential for fertilization or development initiation.
- The inhibition of unfertilized eggs is likely not solely due to low oxygen consumption rates, except possibly in sea urchins.
- Fertilization's key aspect may lie in overcoming egg inhibition, with oxygen consumption changes being a consequence rather than the cause.
