Group Leader

Marta Shahbazi

Cell fate decisions in the early mammalian embryo

Marta Shahbazi
Group Members
  • Viviane de Souza Rosa
  • Miguel Ángel Ortiz Salazar
  • Rina Sakata
  • Nanami Satoh
  • Luca Schwarz
  • Anfu Wang

Embryo development starts with the zygote, a single cell that gives rise to the myriad of cell types present in the adult organism. The main goal of our group is to understand how different cells in the early embryo decide to take on different specific identities and functions. Such fate decisions do not occur in isolation, but within an embryo that is acquiring specific shapes. We are studying the mechanisms that ensure the right cell types arise at the right place and at the right time. We focus on the critical stage of mammalian development when the embryo is implanting into the mother’s uterus. This stage is important because it is when the basic body plan is formed and when approximately 30% of human pregnancies fail.

The image shows pluripotent stem cells cultured in 3D. Cells are arranged as epithelial spheroids that surround a central lumen. Delaminated cells have lost contact with the lumen and start to express the differentiation factor Brachyury
3D culture of stem cells showing different cellular identities. F-actin marks cell shapes and Brachyury differentiated cells (Sato et al., Dev Cell, 2024).

Failure of pregnancies can be due to a range of developmental and cellular errors, some of which occur remarkably frequently. For example, aneuploid cells, which contain an abnormal number of chromosomes, are found in approximately 80% of early human embryos. We seek to understand how embryos can sometimes overcome these mistakes and develop normally. To investigate this problem, we analyse supernumerary human embryos from assisted reproductive techniques that are donated for research under a licence from the Human Fertility and Embryology Authority.

The image shows a human embryo in which the different cell lineages have been marked with different colours, and the cell shapes are demarcated.
Human embryo 6 days after fertilisation showing foetal progenitors (marked by OCT4 expression) and placental progenitors (marked by GATA3 expression). F-actin marks cell shapes.

Through our work on both normal and aberrant early human embryogenesis, we aim to understand our developmental origins and how errors during these crucial first days impact human development.

Selected Publications

Integrin signaling in pluripotent cells acts as a gatekeeper of mouse germline entry.Makhlouf A, Wang A, Sato N, Rosa VS, Shahbazi MNSci Adv 10(36): eadk2252 (2024)
Basal delamination during mouse gastrulation primes pluripotent cells for differentiation.Sato N, Rosa VS, Makhlouf A, Kretzmer H, Sampath Kumar A, Grosswendt S, Mattei AL, Courbot O, Wolf S, Boulanger J, Langevin F, Wiacek M, Karpinski D, Elosegui-Artola A, Meissner A, Zernicka-Goetz M, Shahbazi MNDev Cell 59(10): 1252-1268.e13 (2024)
Early human development and stem cell-based human embryo models.Shahbazi MN, Pasque VCell Stem Cell 31(10): 1398-1418 (2024)