[Enzyme activity pattern and metabolic pathways during the early embryogenesis ofAcheta domesticus L.]

To analyse the main pathways of energy supplying metabolism, the following ratios of enzyme activities are measured in different developmental stages and in isolated embryos: GAPDH/CE, GAPDH/HOADH and HOADH/CE. The ratios show that the early stages are equally capable to metabolize carbohydrates and fat, but the enzyme activity pattern resembles more that of exclusively fat consuming insect tissues. Special features of the pattern are the very high ratio of HOADH/CE, as yet not observed in other tissues, and the ratio GAPDH/TIM of 1∶1 differing from the enzyme group of constant proportion. Generally the enzymes of intermediary metabolism exhibit low activities.The eggs contain a considerable supply of fat and a small one (0.1% of fresh weight) of glycogen, which begins to increase during the formation of the germlayer.The respiratory quotient of 0.6-0.7 mounts to 0.8, when the "Körpergrundgestalt" is formed.From the properties of the enzyme activity pattern, the early beginning gluconeogenesis and the height of the respiratory quotient it follows, that during early embryogenesis the break down of fat is realized as the main pathway of energy supplying metabolism.