title: Characterization of Reproductive Dormancy in MaleDrosophila melanogaster.
abstract: Insects are known to respond to seasonal and adverse environmental changes by entering dormancy, also known as diapause. In some insect species, includingDrosophila melanogaster, dormancy occurs in the adult organism and postpones reproduction. This adult dormancy has been studied in female flies where it is characterized by arrested development of ovaries, altered nutrient stores, lowered metabolism, increased stress and immune resistance and drastically extended lifespan. Male dormancy, however, has not been investigated inD. melanogaster, and its physiology is poorly known in most insects. Here we show that unmated 3-6 h old male flies placed at low temperature (11°C) and short photoperiod (10 Light:14 Dark) enter a state of dormancy with arrested spermatogenesis and development of testes and male accessory glands. Over 3 weeks of diapause we see a dynamic increase in stored carbohydrates and an initial increase and then a decrease in lipids. We also note an up-regulated expression of genes involved in metabolism, stress responses and innate immunity. Interestingly, we found that male flies that entered reproductive dormancy do not attempt to mate females kept under non-diapause conditions (25°C, 12L:12D), and conversely non-diapausing males do not mate females in dormancy. In summary, our study shows that maleD. melanogastercan enter reproductive dormancy. However, our data suggest that dormant male flies deplete stored nutrients faster than females, studied earlier, and that males take longer to recover reproductive capacity after reintroduction to non-diapause conditions.
authors.affiliation: Department of Zoology, Stockholm University Stockholm, Sweden.
authors.forename: Olga I
authors.initials: OI
authors.lastname: Kubrak
authors.affiliation: Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University Stockholm, Sweden.
authors.forename: Lucie
authors.initials: L
authors.lastname: Kučerová
authors.affiliation: Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University Stockholm, Sweden.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Theopold
authors.affiliation: Department of Zoology, Stockholm University Stockholm, Sweden.
authors.forename: Sören
authors.initials: S
authors.lastname: Nylin
authors.affiliation: Department of Zoology, Stockholm University Stockholm, Sweden.
authors.forename: Dick R
authors.initials: DR
authors.lastname: Nässel
keywords: Drosophila melanogaster; diapause; mating; metabolism; reproduction