Hypodermic self-insemination as a reproductive assurance strategy
- Ramm, Steven A. ORCID Evolutionary Biology, Bielefeld University, Bielefeld 33615, Germany
- Schlatter, Aline Evolutionary Biology, Zoological Institute, University of Basel, Basel 4051, Switzerland
- Poirier, Maude Evolutionary Biology, Zoological Institute, University of Basel, Basel 4051, Switzerland
- Schärer, Lukas Evolutionary Biology, Zoological Institute, University of Basel, Basel 4051, Switzerland
- 2015-7-22
Published in:
- Proceedings of the Royal Society B: Biological Sciences. - The Royal Society. - 2015, vol. 282, no. 1811, p. 20150660
General Biochemistry, Genetics and Molecular Biology
General Immunology and Microbiology
General Agricultural and Biological Sciences
General Environmental Science
General Medicine
English
Self-fertilization occurs in a broad range of hermaphroditic plants and animals, and is often thought to evolve as a reproductive assurance strategy under ecological conditions that disfavour or prevent outcrossing. Nevertheless, selfing ability is far from ubiquitous among hermaphrodites, and may be constrained in taxa where the male and female gametes of the same individual cannot easily meet. Here, we report an extraordinary selfing mechanism in one such species, the free-living flatworm
Macrostomum hystrix.
To test the hypothesis that adaptations to hypodermic insemination of the mating partner under outcrossing also facilitate selfing, we experimentally manipulated the social environment of these transparent flatworms and then observed the spatial distribution of received sperm
in vivo
. We find that this distribution differs radically between conditions allowing or preventing outcrossing, implying that isolated individuals use their needle-like stylet (male copulatory organ) to inject own sperm into their anterior body region, including into their own head, from where they then apparently migrate to the site of (self-)fertilization. Conferring the ability to self could thus be an additional consequence of hypodermic insemination, a widespread fertilization mode that is especially prevalent among simultaneously hermaphroditic animals and probably evolves due to sexual conflict over the transfer and subsequent fate of sperm.
Self-fertilization occurs in a broad range of hermaphroditic plants and animals, and is often thought to evolve as a reproductive assurance strategy under ecological conditions that disfavour or prevent outcrossing. Nevertheless, selfing ability is far from ubiquitous among hermaphrodites, and may be constrained in taxa where the male and female gametes of the same individual cannot easily meet. Here, we report an extraordinary selfing mechanism in one such species, the free-living flatworm
To test the hypothesis that adaptations to hypodermic insemination of the mating partner under outcrossing also facilitate selfing, we experimentally manipulated the social environment of these transparent flatworms and then observed the spatial distribution of received sperm
. We find that this distribution differs radically between conditions allowing or preventing outcrossing, implying that isolated individuals use their needle-like stylet (male copulatory organ) to inject own sperm into their anterior body region, including into their own head, from where they then apparently migrate to the site of (self-)fertilization. Conferring the ability to self could thus be an additional consequence of hypodermic insemination, a widespread fertilization mode that is especially prevalent among simultaneously hermaphroditic animals and probably evolves due to sexual conflict over the transfer and subsequent fate of sperm.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1098/rspb.2015.0660
- ISSN 0962-8452
- Persistent URL
- https://sonar.ch/global/documents/174168
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