Insights & Perspectives
Retroviruses facilitate the rapid evolution of the mammalian placenta
Article first published online: 19 JUL 2013
© 2013 WILEY Periodicals, Inc.
Volume 35, Issue 10, pages 853–861, October 2013
How to Cite
Chuong, E. B. (2013), Retroviruses facilitate the rapid evolution of the mammalian placenta. Bioessays, 35: 853–861. doi: 10.1002/bies.201300059
- Issue published online: 14 SEP 2013
- Article first published online: 19 JUL 2013
- Stanford Genome Training. Grant Number: E.B.C.; T32 HG000044
- National Science Foundation Graduate Research Fellowship. Grant Number: E.B.C.; 2008052909
Vol. 36, Issue 8, 807, Article first published online: 4 JUN 2014
- endogenous retroviruses;
- regulatory evolution
The mammalian placenta exhibits elevated expression of endogenous retroviruses (ERVs), but the evolutionary significance of this feature remains unclear. I propose that ERV-mediated regulatory evolution was, and continues to be, an important mechanism underlying the evolution of placental development. Many recent studies have focused on the co-option of ERV-derived genes for specific functional adaptations in the placenta. However, the co-option of ERV-derived regulatory elements could potentially lead to the incorporation of entire gene regulatory networks, which, I argue, would facilitate relatively rapid developmental evolution of the placenta. I suggest a model in which an ancient retroviral infection led to the establishment of the ancestral placental developmental gene network through the co-option of ERV-derived regulatory elements. Consequently, placental development would require elevated tolerance to ERV activity. This in turn would expose a continuous stream of novel ERV mutations that may have catalyzed the developmental diversification of the mammalian placenta.