Male pygmy hippopotamus influence offspring sex ratio
Open Access
- 1 January 2012
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Communications
- Vol. 3 (1), 697
- https://doi.org/10.1038/ncomms1700
Abstract
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.This publication has 35 references indexed in Scilit:
- High Levels of DNA Fragmentation in Spermatozoa Are Associated with Inbreeding and Poor Sperm Quality in Endangered Ungulates1Biology of Reproduction, 2010
- Aspects of the management of cheetahs, Acinonyx jubatus jubatus, trapped on Namibian farmlandsBiological Conservation, 2003
- DISTORTED SEX RATIO AT BIRTH IN THE CAPTIVE PYGMY HIPPOPOTAMUS, HEXAPROTODON LIBERIENSISJournal of Mammalogy, 2002
- Approximate Is Better than "Exact" for Interval Estimation of Binomial ProportionsThe American Statistician, 1998
- On Sex Ratio and Coital Rate: A Hypothesis Without FoundationCurrent Anthropology, 1995
- On housing the Pygmy hippopotamusInternational Zoo Yearbook, 1978
- Sex Ratio in the Golden Hamster before Uterine ImplantationNature, 1958
- THE RELATIONSHIP BETWEEN PARENTAL AGE, BIRTH ORDER and THE SECONDARY SEX RATIO IN HUMANSAnnals of Human Genetics, 1956
- The influence of excessive sexual activity of male rabbits. II. On the nature of their offspringJournal of Experimental Zoology, 1918
- THE ACCESSORY CHROMOSOME—SEX DETERMINANT?The Biological Bulletin, 1902