Effects of temperature on Drosophila—VII. Glutamate-aspartate transaminase activity

Abstract

• 1.

  1. Glutamate-aspartate transaminase activity in homogenates of young adults is reported for stocks of Drosophila melanogaster, D. immigrans, D. pseudoobscura and D. willistoni grown at 15 and 25°C.

• 2.

  2. Female D. melanogaster acclimated at 25°C, have lower glutamate-aspartate transaminase activity, measured at 20°C, than do those grown at the “normal” temperature of 15°C.

• 3.

  3. Glutamate-aspartate transaminase activity of young adult males and females of D. immigrans acclimated at 25°C is lowe than that of flies grown at 15°C when measured at 20°C.

• 4.

  4. Transaminase activity does not vary with acclination temperature in young adults of the two stenothermal species, D. pseudoobscura and D. willistoni.

• 5.

  5. The data reported support the theory that eurythermal species at Drosophila have greater capacity for physiological adaptation than do stenothermal species. It is theorized that respiratory control in Drosophila may be related to rates of amino acid conversion and the level of substrates entering the Krebs cycle.