The glyoxylate cycle and the conversion of triglycerides to carbohydrates in developing eggs of Ascaris lumbricoides

Abstract

1. 1. It is known that stored trehalose and glycogen are metabolized during the first 10 days of development of Ascaris lumbricoides eggs and are completely resynthesized from triglyceride fatty acids during the next 15 days. It has now been found that changes in the specific activities of the glyoxylate cycle enzymes, isocitrate lyase and malate synthase closely parallel changes in the rate of carbohydrate resynthesis as well as changes in the rate of incorporation of label from absorbed U- 14C-palmitate in both trehalose and glycogen. 2. 2. The gluconeogenic enzymes phosphoenolpyruvate carboxykinase and fructose-1,6-diphosphatase are present throughout development. 3. 3. The glyoxylate cycle and the conversion of th eresulting 4-carbon dicarboxylic acids to trehalose and glycogen account for the unique synthesis of carbohydrate from higher fatty acids. 4. 4. Neither isocitrate lyase nor malate synthase could be detected in homogenates of adult A. lumbricoides muscle.