Summary: The rate of oxygen uptake by single macroplasmodia of increased in two steps during each synchronous mitotic cycle. Plateaux in the respiratory pattern, of 0.22 cycles duration, occurred in mid-interphase and in the period up to and including mitosis. A fall in the rate of respiration was frequently associated with mitosis itself. This pattern of respiration continued for more than 10 mitotic cycles after inoculation and was unaffected by omission of an initial routine period of starvation. A similar stepped pattern of respiration was observed in synchronously germinating spherules during the period between outgrowth and the first mitosis. The specific activities of succinate dehydrogenase, fumarase and malate dehydrogenase remained relatively constant during the mitotic cycle, while fluctuations in cytochrome oxidase activity paralleled those in specific respiratory activity. Possible mechanisms for controlling the pattern of respiration are discussed with reference to published data on protoplasmic streaming and ATP concentrations during the mitotic cycle.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error