Sex determination in mammals — Before and after the evolution of SRY

@article{Wallis2008SexDI,
  title={Sex determination in mammals — Before and after the evolution of SRY},
  author={M. C. Wallis and Paul D. Waters and Jennifer A. Marshall Graves},
  journal={Cellular and Molecular Life Sciences},
  year={2008},
  volume={65},
  pages={3182-3195}
}
Abstract.Therian mammals (marsupials and placentals) have an XX female: XY male sex chromosome system, which is homologous to autosomes in other vertebrates. The testis-determining gene, SRY, is conserved on the Y throughout therians, but is absent in other vertebrates, suggesting that the mammal system evolved about 310 million years ago (MYA). However, recent work on the basal monotreme mammals has completely changed our conception of how and when this change occurred. Platypus and echidna… 

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