Genetic arquitecture of odor-guided behavior in Drosophila melanogaster larvae.

LAVAGNINO, N; FANARA, JJ

San Paulo, Brasil

Congreso; 51º CONGRESO BRASILEIRO DE GENÉTICA; 2005

Adaptive evolution is driven by the interaction between animals and their environment, hence the expressions of most characters is influenced by multiple genes and multiple environmental factors. In these sense olfactory behavior (OB) is a crucial Quantitative Complex Trait because permits it animals to locate food, avoid predator and find mates. Significant progress have been made in Drosophila melanogaster to understand it’s functional organization and genetic bases. However, this progress was exclusively focuss on the adult life stage, so the aim of this work is to study the genetic arquitecture of OB in Drosophila melanogaster larvae using a loss-of-function analysis. We screened 59 co-isogenics single P-element inserted lines to identify genes affecting the expression of olfactory behaviour. A simple and repeatable comportamental assay was performed to quantify the response of larvae to two chemical stimulus: Propionic Acid and Benzaldehyde (both atractors). Statistical analysis revealed a significant line effect suggesting mutational genetic variance for both chemicals. This suggest that mutagenesis affects genes involved in the expression of the character. Comparison of the mutated lines with a control line free of P-elements allow us to identify the lines responsible for this variance. With these lines and because the genome sequence of Drosophila melanogaster is available on the net we were able to identify the genes mutated by the P-elements in this lines. Our results indicate that only some of the genes are involved in the expression of the trait in both stages of the life cycle: larvae and adult, suggesting that the genetic arquitecture of odor-guided behavior change along the life cycle of the flies.