Complete human day 14 post-implantation embryo models from naive ES cells

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Human Embryogenesis

Background:

• Studying human post-implantation development is challenging due to ethical and technical limitations.
• Existing embryo-like models lack the complex organization of early human conceptus tissues.
• Previous studies successfully created mouse stem cell-based embryo models (SEMs).

Purpose of the Study:

• To develop human embryo-like models using genetically unmodified human naive embryonic stem cells.
• To recapitulate the spatial organization and morphogenesis of early post-implantation human embryos.
• To create a platform for studying previously inaccessible stages of human development.

Main Methods:

• Utilized genetically unmodified human naive embryonic stem cells.
• Cultured cells in human enhanced naive stem cell medium.
• Allowed stem cells to self-assemble into structured stem-cell-based embryo models (SEMs).

Main Results:

• Developed fully integrated human SEMs that mirror post-implantation human embryo organization.
• SEMs recapitulate key developmental events up to 13-14 days post-fertilization (Carnegie stage 6a).
• Observed formation of embryonic disc, bilaminar disc, yolk sac, chorionic cavity, and trophoblast differentiation.

Conclusions:

• Human SEMs provide a novel model for studying early human development.
• This platform enables investigation of human embryogenesis up to the peri-gastrulation stage.
• The models offer insights into developmental processes previously difficult to study.