Reproductive biologists are developing an unusual way to produce farm animals with desirable traits: injecting surrogate fathers — whose own sperm production has been crippled by gene editing — with sperm-producing stem cells from another male that pass along ‘elite’ genes to offspring.
McGrew and his team have gone on to transplant stem cells into developing female embryos that carry the disabled DDX4 gene.
At the Plant and Animal Genome meeting in San Diego, California, in January, Oatley presented the results of his efforts to transplant sperm-producing stem cells into his surrogate pig sires.
Next month, at the Transgenic Technology Meeting in Kobe, Japan, Oatley plans to present additional data showing that he can achieve normal fertility in surrogate mouse sires, even when he transplants the sperm-producing stem cells from a genetically dissimilar strain of mice.
And Bhanu Telugu, a reproductive biologist at the University of Maryland in College Park, says that tweaking the procedure to create a surrogate pig sire — such as transplanting the cells when the surrogate is younger — could boost the number of sperm produced.