The effect of temperature on the number and gender of fruit flies (Drosophila melanogaster) reaching adulthood

Abstract

In Drosophila melanogaster, gender and duration of heat exposure can alter the level of the induced heat shock protein Hsp70, which in turn may influence individual heat tolerance. It has not been fully explored whether gender and long-term heat exposure affect the time from larval stages to adulthood in D. melanogaster. To examine this further, wild-type D. melanogaster larvae were incubated at 17 °C, 25 °C or 30 °C until the adult stage was observed. The larvae were divided into 12 food vials, each containing 5 larvae. From these 12 vials, four food vials were incubated for each temperature treatment. We recorded the gender and maturation time daily for 18 consecutive days except on weekends and found that 18 days were insufficient to observe adult stage D. melanogaster in the 17 °C treatment. Our results showed that the 25 °C treatment had a higher male to female ratio (12:3) than the 30 °C (6:4) treatment. Furthermore, D. melanogaster at 25 °C showed a longer developmental time to reach adulthood than 30 °C treatment. From our results we did not find statistical support for an effect of temperature on the number of males and females reaching the adult stage. We did however, find that temperature has a significant effect on developmental time to reach adulthood, and may relate to the role of Hsp70, but this effect was not observed between genders.