Changes across development influence visible and cryptic natural variation of Drosophila melanogaster olfactory response.

LAVAGNINO N; FANARA, JJ

EVOLUTIONARY BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2017 vol. 43 p. 96 - 108

0071-3260

Relative to an equivalent source of variationthat do not present a hidden state, cryptic genetic variationis likely to be an effective source for possible adaptations attimes of atypical environmental conditions. In addition toenvironmental perturbations, it has also been proposed thatgenetic disturbances can generate release of cryptic geneticvariation. The genetic basis and physiology of olfactoryresponse in Drosophila melanogaster is being studied profusely,but almost no analysis has addressed the question ifpopulations harbor cryptic genetic variation for this traitthat only manifests when populations experiences a typicalor novel conditions. We quantified olfactory responses tobenzaldehyde in both larval and adult lifecycle stagesamong samples of chromosome two substitution linesextracted from different natural populations of Argentinaand substituted into a common inbred background. We alsoevaluated whether an effect of genetic background change,occurred during chromosome substitution, affect larval andadult olfactory response in terms of release of crypticgenetic variation. Results indicate the presence of geneticvariation among chromosome substitution lines in bothlifecycle stages analyzed. The comparative analysesbetween chromosome 2 substitution lines and isofemalelines used to generate the chromosome 2 substitution linesshown that only adults exhibited decanalizing process forolfactory response to benzaldehyde in natural populationsof D. melanogaster, i.e., release of hidden genetic variation.We propose that this release of hidden genetic variation inadult flies is a consequence of the shift in genetic backgroundcontext that happens in chromosome 2 substitutionlines, that implies the disruption of natural epistatic interactionsand generation of novel ones. All in all, we havefound that changes across D. melanogaster developmentinfluence visible and cryptic natural variation of olfactorybehavior. In this sense, changes in the genetic backgroundcan affect gene-by-gene interactions (epistasis) generatingdifferent or even novel phenotypes as consequence ofphenotypic outcome of cryptic genetic variation