GENETICS VARIATION OF STARVATION RESISTANCE IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER.

GOENAGA, J; FANARA, JJ; HASSON, E

San Pablo, Brasil

Congreso; 51 Congreso Brasilero de Genetica; 2005

The analysis of genetic variation in stress-resistance characters, such as starvation-resistance, is essential to understand adaptation and biogeographic patterns in organisms, which are often exposed to seasonal differences in the availability of resources. We intend to study and analyze intra and interpopulation variation in starvation resistance among Drosophila melanogaster natural populations. Starvation resistance was measured in isofemale lines from 8 natural populations collected at different sites selected from a latitude and altitude transect across Western Argentina. Fifteen isofemale lines were studied from each population. Flies were starved and we determine the time elapsed from the onset of the experiment to death of all flies. The essay for starvation was conducted for each sex separately. The results showed a clear sexual dimorphism, with female being significantly more resistant than males. In addition, we also detected significant differences in stress resistance among populations. Our data did not reveal any clear clinal trend in variation in starvation resistance deviation. The interaction between sex and population was also significant, showing that the magnitude of the sexual dimorphism varied between populations. Also, significant differences in starvation resistance were observed within populations, revealing that variation in starvation resistance has a genetic basis. In conclusion, this study shows that natural populations are highly variable in starvation resistance, partly due to genetic factors