Microparasites and placental invasiveness in eutherian mammals

Isabella Capellini, Charles L. Nunn, Robert A. Barton

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Placental invasiveness - the number of maternal tissue layers separating fetal tissues from maternal blood - is variable across mammalian species. Although this diversity is likely to be functionally important, variation in placental invasiveness remains unexplained. Here we test the hypothesis that increased risk of transplacental transmission of pathogens from the mother to the fetus promotes the evolution of non-invasive placentation, the most likely derived condition in eutherian mammals. Specifically, we predict that non-invasive placentation is associated with increased microparasite species richness relative to more invasive placental types, based on the assumption that higher numbers of microparasites in a population reflects greater risk of transplacental transmission to fetuses. As predicted, higher bacteria species richness is associated with non-invasive placentation. Protozoa species richness, however, shows the opposite pattern. Because invasive placentae facilitate the transfer of maternal antibodies to the fetus, we propose that the ancestral condition of invasive placentation is retained under selection for protection of newborns from higher risk of postnatal protozoan infection. Hence, our findings suggest that a tradeoff exists between protection against bacterial infection prenatally and protozoan infection postnatally. Future studies are needed to investigate how maternal prevalence of infection and the relative pre-versus postnatal risk of fetal infection by different microparasite groups vary among mammalian hosts in relation to placental invasiveness.

Original languageEnglish
Article numbere0132563
JournalPLoS ONE
Volume10
Issue number7
DOIs
Publication statusPublished - 13 Jul 2015

Bibliographical note

This article was recommended by the Faculty 1000 Women’s Health Panel

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

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  • Activities

    • 2 Invited talk
    • 1 Invited or keynote talk at national or international conference

    The evolution of the mammalian placenta: between cooperation and conflict

    Isabella Capellini (Invited speaker)

    Feb 2015

    Activity: Talk or presentation typesInvited talk

    The evolution of the placenta: between cooperation and conflict

    Isabella Capellini (Invited speaker)

    Mar 2014

    Activity: Talk or presentation typesInvited talk

    Maternal investment and the evolutionary development of brain size in mammals

    Isabella Capellini (Keynote speaker)

    Jun 2014

    Activity: Talk or presentation typesInvited or keynote talk at national or international conference

    Prizes

    BBSRC/NERC Research Grant (£312K; BB/E014593/1; 50% ownership)

    Capellini, Isabella (Recipient), 01 Jan 2008

    Prize: Prize (including medals and awards)

  • Cite this