The Drosophila fat body modulates sexually dimorphic responses to stress. Wendi S. Neckameyer, Kathryn J. Argue. Dept Pharmac & Physiol Sci, St Louis Univ School Med, St Louis, MO.

   As for mammals, the stress response in Drosophila melanogaster is sexually dimorphic. However, unlike mammals, the sex determination pathway in Drosophila is well established, making this an ideal system to identify factors involved in the modulation of sexually dimorphic behavioral responses to stress. In this study, we show that the fat body, which has been shown to be important for body size, energy homeostasis, and sex determination, is a dynamic tissue that changes in response to stress in a sexually and temporally dimorphic manner. Manipulation of the sex determination pathway in the fat body via targeted expression of the transcription factors transformer and transformer2, was able to change physiological output in response to starvation and oxidative stress to that of the opposite sex. These data suggest that the fat body in head tissue may serve as the functional analogue of the mammalian pituitary gland. Additionally, our data uncover the possibility of additional downstream targets for transformer that are separate from the sex determination pathway that can influence behavioral responses.