MITOCHONDRIAL OXIDATIONS OF FATTY ACIDS IN BLOWFLY, LUCILIA

Measurements of 14CO2 released from labelled fatty acids indicated that the fatty acid oxidase in the blowfly, Lucilia cuprina, is first detectable 2 to 3 days before adult emergence, reaches maximal activity at about emergence, then declines to an extremely low level a week after emergence. Freezing and thawing the mitochondria from mature flies did not increase the oxidation which therefore does not appear to be limited by sarcosomal impermeability. Developing thoracic mitochondria isolated on the basis of differences in size and specific gravity showed variations in the distribution of butyrate dehydrogenase-INT reductase. Most of the activity was in the smaller particles, but was equally distributed in particles of different specific gravities. These findings are considered in relation to the development of the flight muscle sarcosomes; the rôle of fat in energizing adult development is discussed. © 1969.