There has been many many experiments where they take Stem Cell and replace the DNA, or change the DNA. Transgenic mice are the most studied. https://www.criver.

There has been many many experiments where they take Stem Cell and replace the DNA, or change the DNA. Transgenic mice are the most studied. https://www.criver.com/products-services/research-models-services/genetically-engineered-model-services/transgenic-mouse-rat-model-creation/transgenic-mice?region=3601 https://www.criver.com/products-services/research-models-ser... There have been succesfull experiments with xeno-pregnancies aka interspecific pregnancy. https://en.wikipedia.org/wiki/Interspecific_pregnancy#:~:text=Interspecific%20pregnancy%20(literally%20pregnancy%20between,another%20species%20than%20the%20carrier https://en.wikipedia.org/wiki/Interspecific_pregnancy#:~:tex.... With current technology, we very much do indeed experiment with DNA of animals. As for making DNA from raw materials, that is what DNA printers to. see https://en.wikipedia.org/wiki/Artificial_gene_synthesis https://en.wikipedia.org/wiki/Artificial_gene_synthesis