Researchers at the Guangzhou Institutes of Biomedicine and Health in China edited pig embryos so they could not grow their own early kidney structure, then injected human stem cells engineered with two extra survival genes into the embryos to see if human cells would fill the gap.
The human cells survived and organized themselves into a structure called a mesonephros, an early, transient kidney precursor, developing in an organized way inside the pig embryos through day 28 of development, a level of organization earlier human-pig embryo work had not reached.
The survival genes were necessary because human cells are normally outcompeted or eliminated in another species' embryo well before they can build any real tissue. The embryos were not brought past day 28 and were never intended to develop further, so the work answered a feasibility question about growing early human organ tissue in a pig, not a step toward a transplantable kidney.
Read the original study
Wang et al., Cell Stem Cell, 2023 · doi.org/10.1016/j.stem.2023.08.003
A human organ's first draft, grown in a pig.
Source
- Wang, J., Xie, W., Li, N., Li, W., Zhang, Z., Fan, N., Ouyang, Z., Zhao, Y., Lai, C., Li, H., Chen, M., Quan, L., Li, Y., Jiang, Y., Jia, W., Fu, L., Mazid, M. A., Zhu, Y., Maxwell, P. H., . . . Lai, L. (2023). Generation of a humanized mesonephros in pigs from induced pluripotent stem cells via embryo complementation. Cell Stem Cell, 30(9), 1235–1245.e6. https://doi.org/10.1016/j.stem.2023.08.003