title: Intense sperm-mediated sexual conflict promotes reproductive isolation in Caenorhabditis nematodes.
abstract: Conflict between the sexes over reproductive interests can drive rapid evolution of reproductive traits and promote speciation. Here we show that inter-species mating between Caenorhabditis nematodes sterilizes maternal individuals. The principal effectors of male-induced harm are sperm cells, which induce sterility and shorten lifespan by displacing conspecific sperm, invading the ovary, and sometimes breaching the gonad to infiltrate other tissues. This sperm-mediated harm is pervasive across species, but idiosyncrasies in its magnitude implicate both independent histories of sexually antagonistic coevolution within species and differences in reproductive mode (self-fertilizing hermaphrodites versus females) in determining its severity. Consistent with this conclusion, in androdioecious species the hermaphrodites are more vulnerable, the males more benign, or both. Patterns of assortative mating and a low incidence of invasive sperm occurring with conspecific mating are indicative of ongoing intra-specific sexual conflict that results in inter-species reproductive incompatibility.
authors: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
authors: Janice J
authors: JJ
authors: Ting
authors: Department of Biology, University of Maryland, College Park, Maryland, United States of America.
authors: Gavin C
authors: GC
authors: Woodruff
authors: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
authors: Gemma
authors: G
authors: Leung
authors: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
authors: Na-Ra
authors: NR
authors: Shin
authors: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
authors: Asher D
authors: AD
authors: Cutter
authors: Department of Biology, University of Maryland, College Park, Maryland, United States of America.
authors: Eric S
authors: ES
authors: Haag
mesh_terms: D000818:Animals; D002107:Caenorhabditis / Q000502:physiology*; D005260:Female; D057850:Hermaphroditic Organisms / Q000502:physiology; D007246:Infertility / Q000209:etiology; D007314:Insemination; D008297:Male; D012098:Reproduction / Q000502:physiology*; D060047:Reproductive Isolation; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D013094:Spermatozoa / Q000502:physiology*