title: Winter is coming: hibernation reverses the outcome of sperm competition in a fly.
abstract: Sperm commonly compete within females to fertilize ova, but research has focused on short-term sperm storage: sperm that are maintained in a female for only a few days or weeks before use. In nature, females of many species store sperm for months or years, often during periods of environmental stress, such as cold winters. Here we examine the outcome of sperm competition in the fruit fly Drosophila pseudoobscura, simulating the conditions in which females survive winter. We mated females to two males and then stored the female for up to 120 days at 4°C. We found that the outcome of sperm competition was consistent when sperm from two males was stored for 0, 1 or 30 days, with the last male to mate fathering most of the offspring. However, when females were stored in the cold for 120 days, the last male to mate fathered less than 5% of the offspring. Moreover, when sperm were stored long term the first male fathered almost all offspring even when he carried a meiotic driving sex chromosome that drastically reduces sperm competitive success under short-term storage conditions. This suggests that long-term sperm storage can radically alter the outcome of sperm competition.
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool, UK.
authors.forename: P
authors.initials: P
authors.lastname: Giraldo-Perez
authors.affiliation: Division of Microbial Ecology, University of Vienna, Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Herrera
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool, UK.
authors.forename: A
authors.initials: A
authors.lastname: Campbell
authors.affiliation: Centre for Ecology and Conservation, Biosciences, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK.
authors.forename: M L
authors.initials: ML
authors.lastname: Taylor
authors.affiliation: Centre for Ecology and Conservation, Biosciences, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK.
authors.forename: A
authors.initials: A
authors.lastname: Skeats
authors.affiliation: Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
authors.forename: R
authors.initials: R
authors.lastname: Aggio
authors.affiliation: Centre for Ecology and Conservation, Biosciences, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK.
authors.forename: N
authors.initials: N
authors.lastname: Wedell
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool, UK.
authors.forename: T A R
authors.initials: TA
authors.lastname: Price
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004330:Drosophila / Q000502:physiology*; D005260:Female; D006605:Hibernation / Q000502:physiology*; D008297:Male; D012098:Reproduction; D012621:Seasons; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology; D013997:Time Factors
keywords: Drosophila pseudoobscura; long-term sperm storage; meiotic drive; overwintering; paternity share; polyandry; selfish genetic element; sperm competition; sperm storage