Body size in Drosophila: genetic architecture, allometries and sexual dimorphism.

CARREIRA, V.; MENSCH, J; FANARA, J.J.

HEREDITY

NATURE PUBLISHING GROUP

Año: 2009 vol. 102 p. 246 - 256

0018-067X

Even though substantial progress has been made toelucidate the physiological and environmental factors underpinningdifferences in body size, little is known about itsgenetic architecture. Furthermore, all animal species bear aspecific relationship between the size of each organ andoverall body size, so different body size traits should beinvestigated as well as their sexual dimorphism that mayhave an important impact on the evolution of body size. Wehave surveyed 191 co-isogenic lines of Drosophila melanogaster,each one of them homozygous for a single P-elementinsertion, and assessed the effects of mutations on differentbody size traits compared to the P-element-free co-isogeniccontrol. Nearly 60% of the lines showed significant differenceswith respect to the control for these traits in one orboth sexes and almost 35% showed trait- and sex-specificeffects. Candidate gene mutations frequently increased bodysize in males and decreased it in females. Among the 92genes identified, most are involved in development and/ormetabolic processes and their molecular functions principallyinclude protein-binding and nucleic acid-binding activities.Although several genes showed pleiotropic effects in relationto body size, few of them were involved in the expression ofall traits in one or both sexes. These genes seem to beimportant for different aspects related to the generalfunctioning of the organism. In general, our results indicatethat the genetic architecture of body size traits involves alarge fraction of the genome and is largely sex and traitspecific.