Abstract
female specific independent of transformer (fit) expression increases
in D. melanogaster courting males and in both sexes after mating. In
contrast, fit expression decreases during starvation in males and
females. fit expression is enriched in the fat body, an insect tissue
that is analogous to vertebrate fat. The fat body stores excess
nutrients that are mobilized during starvation. This information led us
to investigate how fit mutants respond to starvation. We found that
both fit mutant males and females are starvation resistant, a
phenotype that is reversed in males by fit expression in the fat body.
fit mutants may be starvation resistant because they consume more
food than controls prior to starvation. To test this, we monitored the
total amount of food consumed from eclosion until starvation using
the CAFE assay. Another possible explanation for starvation
resistance is either increased storage before or slower use of lipids in
the fat body during starvation. We used Nile Red and Oil Red O to
stain lipids in the fat bodies of fed fit mutants and controls to
examine whether the absence of fit leads to altered lipid storage. We
also examined the fat bodies of fit mutants and controls throughout
starvation to determine when lipid stores are depleted.