Abstract
Mitochondrial uncoupling is one of the most important cellular mechanisms of body heat production, in which the chemical energy used to produce ATP in the respiratory chain (RC) is dissipated as heat. In plants such as the sacred lotus, heating of the floral organs is accomplished by the presence of alternative oxidase (AOX) in the RC, which bypass complexes III and IV, without proton pumping to the intermembrane space, thus reducing the electrochemical potential used to synthesize ATP. In animals, this mechanism has not yet been described, probably because the best studied groups, vertebrate and arthropod, independently lost the AOX-coding gene throughout evolution. Interestingly, when AOX was expressed transgenetically in Drosophila melanogaster, mouse and human cells in culture, the enzyme proved to be functional and provided to these experimental models an improvement in the conditions associated with mitochondrial dysfunctions, however its possible thermogenic consequences have not been analyzed. This project aims to investigate the physiological and metabolic effects of AOX expression in D. melanogaster, testing the hypothesis that the presence of this enzyme increases the body temperature of these insects. AOX-expressing lines at different levels will be subjected to different temperatures, including severe stress conditions, to analyze the phenotypic, molecular and biochemical effects of this enzyme during the development and adult stage of these flies. The combination of infrared thermography, expression of thermal stress genes and mitochondrial oxygen consumption will certainly contribute to the understanding of the biology of AOX and its thermogenic potential in animals. (AU)
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