Genetic Architecture of Developmental Time in Drosophila melanogaster.

MENSCH JULIÁN; LAVAGNINO NICOLÁS; CARREIRA VALERIA; FANARA JUAN JOSÉ

Guarujá, Sao Paulo, Brasil

Congreso; 2nd International 2nd Meeting of the Latin American Society of Developmental Biology; 2005

Latin American Society of Developmental Biology

Organisms with metamorphosis are characterized by drastic morphological,physiological and behavioural changes during their ontogeny. In this sense, the time toreach the reproductive age is a complex trait with great adaptive relevance known asdevelopmental time. In models organisms, ecological aspects of this trait has beendeeply analyzed, but not much efforts have been made to study the genetic architectureof this adaptive character.The aim of this work is to study the basis and genetic architecture of developmentaltime in Drosophila melanogaster. In this sense, a P-element insertional mutagenesismethodology was employed for genetic screening. We screened 200 independent coisogenicP-elements insertion lines to identify candidate genes affecting developmentaltime. The screening consist in finding phenotypic differences between P-elements linesand a co-isogenic control line P-element insertion free. In order to identify the mutatedgenes, nucleotide sequences flanking the P-element insertion were employed as “insilico” probes to search homologous regions in the D. melanogaster genome.The results show a highly significant mutational variance among single P-elementinsertion lines for developmental time. In addition we detected a significant line by sexinteraction suggesting that the expression of the gene inserted depends on the sexanalyzed. In most of the lines that showed a highly significant difference indevelopmental time as compared to control line, we performed a second phenotypicassessment to confirm our first screening. In this case, five of the retested lines wereconfirmed, indicating that those genes are involved in this adaptive trait. Particularly,the P-element insertion line affecting the expression of CG 18265 gene prolonged morethan two days developmental time in both sexes. Surprisingly, this line does not showedsignificant differences as compared to the control under different temperature conditions(25º C and 17º C) suggesting a significant genotype by environment interaction. Basedon this results, we discuss the relevance of genetics as well the environmentalcomponents in the phenotypic model of this adaptive trait.