Methoprene and 20-OH-Ecdysone affect male production in Daphnia pulex
✍ Scribed by Jane K. Peterson; Donna R. Kashian; Stanley I. Dodson
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 83 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0730-7268
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Exposure of Daphnia pulex to the insecticide and juvenile hormone‐mimic methoprene resulted in a decrease in the incidence of all‐male broods and an increase in the incidence of all‐female broods compared with controls. These effects were observed at nominal concentrations of 10 and 100 μg/L, within the upper range of concentrations at which methoprene is applied in the environment. Because methoprene has been found to bind to the mammalian retinoid × receptor, we also tested the effects of retinoic acid on Daphnia reproduction. Neither 9‐cis‐retinoic acid nor all‐trans‐retinoic acid had any observable effect. Because juvenile hormone and ecdysteroids interact in many insect systems, we also exposed Daphnia to 20‐OH‐ecdysone. Exposure to the crustacean hormone 20‐OH‐ecdysone at levels of 1 and 10 μg/L resulted in an increase in all‐male broods and a decrease in all‐female broods, but 100 μg/L 20‐OH‐ecdysone resulted in a decrease in all‐male broods and an increase in all‐female broods. Our results suggest that juvenile hormone and ecdysteroids might play a role in the Daphnia sex determination system.