The abstract is read at the publisher; the summary is JClub's.
A newly evolved maternal cell type in poeciliid fish likely enabled the transition from egg-laying to live-bearing and repeatedly seeded placenta formation in five independent origins.
- Why it matters: New organs are hard to trace because most have ancient origins, but poeciliids provide a rare case with multiple recent placenta evolutions.
- What they did: Using sister species pairs with and without placentas, the study mapped molecular and cellular drivers across five independent placenta origins, identifying a maternal cell type co-opted from an ovarian cell type’s gene regulatory network.
- The result: The same maternal cell type, with the embryonic yolk sac, was repeatedly co-opted to form placentas, showing pathway-level convergence (e.g., lipid metabolism and vesicle-mediated transport) while relying on distinct genes across species.
The findingWhy it mattersWhat they didThe result
AI summary of the abstract · may contain errors · not medical advice · read the paper.