Gene expression phylogenies and ancestral transcriptome reconstruction resolves major transitions in the origins of pregnancy
- University of Chicago, United States
- University of Sydney, Australia
- University at Buffalo, State University of New York, United States
Abstract
Structural and physiological changes in the female reproductive system underlie the origins of pregnancy in multiple vertebrate lineages. In mammals, the glandular portion of the lower reproductive tract has transformed into a structure specialized for supporting fetal development. These specializations range from relatively simple maternal nutrient provisioning in egg-laying monotremes to an elaborate suite of traits that support intimate maternal-fetal interactions in Eutherians. Among these traits are the maternal decidua and fetal component of the placenta, but there is considerable uncertainty about how these structures evolved. Previously we showed that changes in uterine gene expression contributes to several evolutionary innovations during the origins of pregnancy (Marinic, Mika, and Lynch 2021). Here we reconstruct the evolution of entire transcriptomes ('ancestral transcriptome reconstruction') and show that maternal gene expression profiles are correlated with degree of placental invasion. These results indicate that an epitheliochorial-like placenta evolved early in the mammalian stem-lineage and that the ancestor of Eutherians had a hemochorial placenta, and suggest maternal control of placental invasiveness. These data resolve major transitions in the evolution of pregnancy and indicate that ancestral transcriptome reconstruction can be used to study the function of ancestral cell, tissue, and organ systems.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting file; Source Data files have been provided for Figures 2, 3 and 5.
Article and author information
Author details
Camilla M Whittington
Funding
March of Dimes Foundation
- Vincent J Lynch
Burroughs Wellcome Fund (1013760)
- Vincent J Lynch
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2022, Mika et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Gene expression phylogenies and ancestral transcriptome reconstruction resolves major transitions in the origins of pregnancy
eLife 11:e74297.
https://doi.org/10.7554/eLife.74297
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