Université de Fribourg

Experimental evolution of olfactory memory in Drosophila melanogaster

Mery, Frederic ; Pont, Juliette ; Preat, Thomas ; Kawecki, Tadeusz J.

In: Physiological and Biochemical Zoology, 2007, vol. 80, no. 4, p. 399-405

In order to address the nature of genetic variation in learning performance, we investigated the response to classical olfactory conditioning in "high-learning" Drosophila melanogaster lines previously subject to selection for the ability to learn an association between the flavor of an oviposition medium and bitter taste. In a T-maze choice test, the seven high-learning lines were better at...

Université de Fribourg

Natural polymorphism affecting learning and memory in Drosophila

Mery, Frederic ; Belay, Amsale T. ; So, Anthony K.-C. ; Sokolowski, Marla B. ; Kawecki, Tadeusz J.

In: Proceedings of the National Academy of Sciences of the United States of America, 2007, vol. 104, no. 32, p. 13051-13055

Knowing which genes contribute to natural variation in learning and memory would help us understand how differences in these cognitive traits evolve among populations and species. We show that a natural polymorphism at the foraging (for) locus, which encodes a cGMP-dependent protein kinase (PKG), affects associative olfactory learning in Drosophila melanogaster. In an assay...

Université de Fribourg

No trade-off between learning ability and parasitoid resistance in Drosophila melanogaster

Kolss, Munjong ; Kraaijeveld, A. R. ; Mery, Frederic ; Kawecki, Tadeusz J.

In: Journal of Evolutionary Biology, 2006, vol. 19, no. 4, p. 1359-1363

Learning ability and immunity to parasites are linked at the physiological level in several insect species. The aim of this work was to investigate the relationship between learning and immunity at an evolutionary level. We tested whether selection for improved learning ability in Drosophila melanogaster led to changes in parasitoid resistance as a correlated response. Similarly, we assayed...

Université de Fribourg

Genetically idiosyncratic responses of Drosophila melanogaster populations to selection for improved learning ability

Kawecki, Tadeusz J. ; Mery, Frederic

In: Journal of Evolutionary Biology, 2006, vol. 19, no. 4, p. 1265-1274

To what extent is adaptive evolution over short timescales repeatable? To address this question, we studied the performance of crosses between replicate Drosophila melanogaster lines previously subject to selection for improved learning response in the context of oviposition substrate choice. Of the 10 pairwise F1 crosses among the five selection lines, four performed in the original learning...

Université de Fribourg

A cost of long-term memory in Drosophila

Mery, Frederic ; Kawecki, Tadeusz J.

In: Science, 2005, vol. 308 (5725), p. 1148

Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of...

Université de Fribourg

An operating cost of learning in Drosophila melanogaster

Mery, Frederic ; Kawecki, Tadeusz J.

In: Animal Behaviour, 2004, vol. 68, p. 589-598

Although the fitness benefits of learning are well understood, we know little about its costs; yet both are essential to understand the evolution of animal learning. We tested the hypothesis that learning has an operating cost, such that an animal repeatedly forced to use its learning ability would show a reduction in some fitness component(s), relative to an animal of the same genotype that does...

Université de Fribourg

The effect of learning on experimental evolution of resource preference in Drosophila melanogaster

Kawecki, Tadeusz J. ; Mery, Frederic

In: Evolution, 2004, vol. 58, p. 757-767

Learning is thought to be adaptive in variable environments, whereas constant, predictable environments are supposed to favor unconditional, genetically fixed responses. A dichotomous view of behavior as either learned or innate ignores a potential evolutionary interaction between the learned and innate components of a behavioral response. We addressed this interaction in the context of...

Université de Fribourg

Experimental Evolutionary Biology of Learning in “drosophila melanogaster”

Mery, Frederic ; Kawecki, Tadeusz (Dir.)

Thèse de doctorat : Université de Fribourg : 2003 ; 1403.

Many animals, including small invertebrates, have the capacity to modify their behaviour based on experience - they can learn. The ability to learn is itself a product of evolution, and the degree to which a given behaviour is modified by learning varies among species and among different types of behaviour. For an evolutionary biologist this raises the question of the conditions under which...