The secret of pregnancy for 100 million years: inside the evolutionary play in the placenta

The pregnancy that lasts for a sufficient period to support the growth of the entire fetus is a distinctive penetration of placenta mammals – a group that includes humans. In the midst of this is the embryonic interface of the mother: the location in the womb where the placenta meets the child with the womb of the mother, and where two genetically distinguished organisms – the mother and the fetus – are in intimate contact and continuous interaction. This facade should achieve an accurate balance: intimate enough to exchange nutrients and signs, but it is protected enough to prevent the mother immune system from the “foreign” fetus refusal genetically.

To reveal the origins and mechanisms behind this complex structure, the team analyzed mono -cell texts – shots of active genes in individual cells – of six types of mammals that represent the main branches of the mammal development tree. These mice and pigs include Guinea (rodents), makak and humans (the main), two other unusual ransoms: TENREC (early placenta mammals) and Obusum (Martian separated from the placenta mammals before the complex placenta develops).

“Atlas of the Mammals’ Carrying

By analyzing cells in the front of the mother of Jenin, the researchers managed to track the evolutionary origin and diversify the types of the main cells concerned. Their focus was on two main players: placenta cells, which arise from the fetus and invade the mother’s tissues, and uterine fleshy cells, which are of the origin of the mother and respond to this invasion.

Using molecular biology tools, the team has identified distinct genetic signatures – patterns of unique genes activity for specific types of cells and their specialized functions. It is worth noting that they have discovered a genetic signature linked to the soft behavior of the fetal placenta cells that were saved in mammals for more than 100 million years. This discovery challenges the traditional view that the gas placenta cells are unique to humans, and instead it reveals that it is a deep reserved feature of mammal development. During this time, the mother’s cells were not fixed either. Plating mammals are found, but not, not the lane, on new forms of hormones, a pivotal step towards long pregnancy and complex pregnancy, and a sign that the fetus and mother can develop each other.

Cellular dialogue: Between cooperation and conflict

To better understand how the Fetal interface-facade, the study tested two influential theories on the development of cellular communication between the mother and the fetus.

The first, the “mystery hypothesis”, predicts that over the evolutionary time, hormonal signals are clearly dedicated to the fetus or mother – a possible protection to ensure clarity and prevent manipulation. The results confirmed this idea: Some signals, including WNT proteins, immune engines, and steroid hormones can be tracked to one source tissue.

The second, the “escalation hypothesis” (or “genetic conflict”), indicates the presence of an evolutionary arms race between the genes of the mother and the fetus – for example, the fetus enhances the fetus’s growth signals while the mother side tries to mix it. This style has been observed in a small number of genes, especially IGF2, which regulates growth. On the whole, evidence indicated the seized cooperative signal.

Daniel J. Standamour, the main author of the study and researcher now in the Department of Evolutionary Biology at the University of Vienna: “These results indicate that development may have preferred more coordination between the mother and the fetus than it was previously assumed.” “The so -called mother strength struggle seems limited to specific genetic areas. Instead of asking whether the pregnancy as a whole is a conflict or cooperation, the most useful question may be: Where is the conflict?”

One cell analysis: the key to evolutionary discovery

The team’s discoveries have become possible by combining two strong tools: one cell science – which embodies the activity of genes in individual cells – and evolutionary modeling techniques that help scientists to rebuild how to consider features in their long predecessors. By applying these methods to the types of cells and their genetic activity, researchers can simulate how cells communicate in different types, and even a glimpse of how this dialogue has evolved over millions of years.

“Our approach opens a new window in the development of complex biological systems – from individual cells to the entire tissue,” says Silvia Basta, the author, first researcher and researcher at the University of Vienna. The study highlights how pregnancy develops, but also provides a new framework for tracking evolutionary innovations at the cell level – visions that can one day improve how we understand, diagnose or treat complications related to pregnancy.

Research was conducted in Mihaela Pavličev laboratories in the Department of Evolutionary Biology, Vienna University, and Gunter Wagner at Yale University. Wagner is a professor of Fakhri at Yale and an older research colleague at the University of Vienna. The study was supported by the John Templeton Foundation and the Austrian Science Fund (FWF).