300099 SE Advanced Topics in Evolutionary Reproductive Biology (2024S)

SS 24: The Evolution of the Fetal-Maternal Relationship
Instructors: Günter P. Wagner & Mihaela Pavličev

Background: viviparity and a long-lasting physiological connection between the embryo/fetus and the mother is a key features of eutherian (so-called placental) mammals. Even though viviparity in the broad sense has evolved many times in animals, the mammalian form of viviparity is special in terms of the level of anatomical and cell biological intimacy of that relationship. It is also a highly unlikely arrangement that raises a host of biological paradoxa. Not the least of which is the immunological paradox, first articulated by Paul Medawar in 1952: why is the fetus not attacked by the mother's adaptive immune system. But there are more, like the inflammation paradox etc. Hence the problem of explaining the evolution of mammalian pregnancy has to focus on the question how evolution overcame these paradoxa.

What will we be discussing?
• What are the patterns of viviparity in vertebrates?
• The structure and evolution of the Fetal-Maternal-Interface.
• What are the principal paradoxa of mammalian pregnancy?
• How did evolution overcome the paradoxa of mammalian pregnancy?

Structure of the Seminar:

1. Introduction to viviparity, the broad strokes
2. Structure and evolution of the Fetal Maternal Interface (FMI)
3. Theories of the FMI
4. Attachment: the cell biological paradox
5. Implantation: the inflammation paradox I
6. Implantation: the inflammation paradox II
7. Placental bed formation: the tissue biological paradox
8. The immunological paradox I
9. The immunological paradox II
10. Decidua hypothesis 1:
11. Decidua hypothesis 2:
12. Progesterone – the hormone of pregnancy
13. Revisiting the theories of FMI

The format will be a mix of short lectures from the instructors and mostly group discussions based on mandatory readings. Each student is expected to provide a short summary and reaction to the reading.
Grades are based on participation and a brief essay on the topic of the seminar.