The origin of platelets enabled the evolution of eutherian placentation

Biol Lett. 2019 Jul 26;15(7):20190374. doi: 10.1098/rsbl.2019.0374. Epub 2019 Jul 10.

Abstract

Invasive placentation with extended pregnancy is a shared derived characteristic unique to eutherian mammals that possess a highly effective system of haemostasis, platelets. These are found in all mammals but no other group of animals. We propose that platelets and megakaryocytes (large polyploid nucleated bone marrow cells that produce platelets) evolved from an ancestral 2 N thrombocyte by polyploidization and that the possession of platelets enabled the evolution of invasive placentation. This could explain why invasive placentation is limited to mammals.

Keywords: evolution; mammal; megakaryocyte; placenta; platelet.

MeSH terms

  • Animals
  • Blood Platelets
  • Eutheria*
  • Female
  • Mammals
  • Placenta
  • Placentation*
  • Pregnancy