Correct self-organization is necessary for proper morphogenesis. a, Time course of the assembly of ETX embryos stained to reveal E-cadherin (monochrome), Oct4 (red) and Gata4 (green). The bottom row of images are magnifications of the images above and show E-cadherin staining around a nascent cavity, as indicated by the dashed yellow lines. The dashed green line indicates the boundary between the ES and XEN compartment. Scale bar, 5 μm. b, Representative images showing Oct4 (red), Gata4 (green), E-cadherin (monochrome) and DAPI (gray) staining in day 4 cadherin OE ETX structures formed by combining E-cadherin OE ES cells with P-cadherin OE TS cells and wild-type XEN cells. ETX structures formed by combining wild-type cells were used as a control. Scale bars, 100 μm. c, Comparison and quantification of joined cavity formation in cadherin OE and control ETX structures. n = 361 (control group) and n = 253 (cadherin OE group). N = 5 for each condition. The data are presented as means ± s.d. Statistical significance was determined by unpaired two-tailed Student’s t-test. d, Representative image showing Oct4 (red), Gata4 (green), laminin (monochrome) and DAPI (blue) staining in day 4 cadherin OE ETX structures formed by combining E-cadherin OE ES cells with P-cadherin OE TS cells and wild-type XEN cells. ETX structures formed by combining wild-type cells were used as a control. Scale bars, 100 μm. e, Quantification of the structures that contained continuous or discontinuous laminin. n = 40 ETX structures per condition. N = 3. The data are presented as means ± s.d. Statistical significance was determined by unpaired two-tailed Student’s t-test. f, Self-organization principles in stem cell-derived ETX embryos. Differential expression of E-, K- and P-cadherins enables the sorting of ES (epiblast-like), XEN (VE-like) and TS (TE-like) stem cells. Wild-type ES cells with low E-cadherin expression and wild-type TS cells with low P-cadherin expression exhibited detrimental global sorting efficiency. This could be overcome by overexpressing E-cadherin in ES cells and P-cadherin in TS cells to increase the efficiency of ETX embryo formation. Proper morphogenesis, including cavity formation, basement membrane formation (purple) and symmetry breaking can only be observed in well-sorted structures. Numerical data are available as source data. Credit: Nature Cell Biology (2022). DOI: 10.1038/s41556-022-00984-y
A team of researchers at the California Institute of Technology, working with one colleague from The Francis Crick Institute and another from the University of Cambridge, have developed a method to grow mouse embryos without using mouse eggs or sperm. Stem cells can be used to grow mouse embryo in a paper published in the journal Nature Cell Biology.
As they develop, mammals differentiate into different types of cells. Stem cells are involved in the processes, but the mechanisms responsible are not known. The researchers grew a mouse embryo that had a beating heart and the beginnings of a brain using three different types of stem cells.
The researchers studied the communication between stem cell groups in mouse embryo. They were able to recognize the elements that went into the communication. Theyciphered the code There are three main types of stem cells that make up the cell mass in early embryo development: pluripotent, which eventually grow to become body tissue, and two other types that grow to become the amnionic sac and placenta. The quantities of each stem cell were noted.
The next step was to create a mouse embryo from stem cells in a lab. The researchers were able to study the embryo's development by growing it.
The researchers added genetically engineered cells to see how the procedure affected the embryo's development. They were able to duplicate some of the brain development issues that have been seen in humans. Their work could help explain what happens when mice miscarry.
More information: Min Bao et al, Stem cell-derived synthetic embryos self-assemble by exploiting cadherin codes and cortical tension, Nature Cell Biology (2022). DOI: 10.1038/s41556-022-00984-y Journal information: Nature Cell Biology
