The learning performance of chico, a long-lived
Drosophila mutant
Anne-Laure Torche
Department of Biology, Unit of Ecology & Evolution
University of Fribourg
Chemin du Musée 10, CH-1700 Fribourg
Keywords: learning performance, aging, insulin, chico, Indy.
ABSTRACT
Learning and memory allow an organism to adjust its behaviour in an adaptive way in
response to a changing environment. These two cognitive functions are agedependent: they decrease with advancing age. Aging and learning abilities are
interdependent but it remains unclear by which process. We asked how the learning
abilities of a long-lived mutant change with age. Is the decrease of learning abilities
delayed as the aging process? Answering this question could help to understand how
aging and learning abilities are related. In this study we compared the learning
abilities of a long-lived drosophila mutant of the insulin pathway, chico, with that of a
wild-type fly at two different ages. We measured the fifteen minutes memory after an
associative conditioning test using odorants as conditioned stimulus and shaking as
unconditioned stimulus. We didn’t find that learning abilities of long-lived and
control flies change differently with age. But we found that long-lived flies show no
decrease of learning abilities with age whereas the control flies do. In order to
distinguish between effect of insulin and between effects of longevity, we made the
same experiment with a long-lived mutant of another pathway than insulin, Indy. The
gene Indy produces a membrane protein that transports Krebs cycle intermediates. We
compared the learning abilities of three Indy mutant lines with wild-type Canton-S at
two different ages. One of the Indy shows normal longevity and therefore served as
control, as the Canton-S. We didn’t find that the decrease of learning abilities with
age depend of the genotype. But we found that the learning abilities of Canton-S
decrease with age whereas it was not the case for the three Indy mutant lines.
Supervisors: Dr. Tadeusz J. Kawecki and Dr. Frederic Mery