Male pygmy hippopotamus influence offspring sex ratio
Open accessAbstract
Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict. Some animal populations are able to shift their birth sex ratio from the expected unity. This study shows, using fluorescencein situhybridization, that in a captive population of pygmy hippopotamus the males appear to be able to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates.
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Fluorescence in situ hybridization, used to determine the primary sex ratio in ejaculates from males (n = 10), revealed an average of 43% of spermatozoa to have a Y chromosome.
“Fluorescence in situ hybridization, used to determine the primary sex ratio in ejaculates from males (n = 10), revealed an average of 43% of spermatozoa to have a Y chromosome (Saragusty et al. 2012).”
From Choeropsis liberiensis (Artiodactyla: Hippopotamidae) (2019) · cites this paper as Saragusty et al. 2012
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- Authors
- Saragusty, J., Hermes, R., Hofer, H., Bouts, T., Göritz, F., & Hildebrandt, T. B.
- Affiliations
- Leibniz Institute for Zoo and Wildlife Research (DE)
- Zoological Society of London (GB)
- Corresponding author
- Saragusty, Joseph
- Venue
- Nature Communications
- Published
- 2012-02-28
- Volume
- 3
- Issue
- 1
- Pages
- 697-697
- ISSN
- 2041-1723 (ISSN-L)
- PMC
- PMC3293421
- OpenAlex
- W2072429490
- Cited by
- 48
- References
- 33
- Citations by year
- 2026: 1 · 2025: 1 · 2024: 2 · 2023: 3 · 2022: 2 · 2021: 4 · 2020: 3 · 2019: 7 · 2018: 4 · 2017: 4 · 2016: 4 · 2015: 6 · 2014: 1 · 2013: 1 · 2012: 4
- FWCI
- 3.93
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Nature Communications (publishedVersion, cc-by-nc-nd)
- Europe PMC (PubMed Central) (publishedVersion, cc-by-nc-nd)
- PubMed Central (publishedVersion, cc-by-nc-nd)
- PubMed (publishedVersion)
- Minerva Access (University of Melbourne) (submittedVersion, cc-by-nc-nd)
- RePEc: Research Papers in Economics (submittedVersion)
- Topics
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Animal Behavior and Reproduction
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
- Keywords
- pygmy hippopotamus, Choeropsis liberiensis, sex ratio, sperm sex ratio, Y-chromosome-bearing sperm, X-chromosome-bearing sperm, sperm competition, sexual conflict, ejaculate composition, fluorescence in situ hybridization
- MeSH terms
- Animals, Female, Male, Mammals, Population Dynamics, Sex Factors, Sex Ratio, Spermatozoa, X Chromosome, Y Chromosome, In Situ Hybridization, Fluorescence, Sex Determination Processes
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