Reproductive scientists have used stem cell technology to create mice from two dads. The breakthrough could be a boon to efforts to save endangered species — and the procedure could make it possible for same-sex couples to have their own genetic children. The scientists, led by Richard Berhringer at the M.D. Anderson Cancer Center in Texas, describe the process in a study posted Wednesday in the journal Biology of Reproduction. Here's how it works:
Cells from a male mouse fetus were manipulated to produce an induced pluripotent stem cell line. These iPS cells are ordinary cells that have been reprogrammed to take on a state similar to that of an embryonic stem cell, which can develop into virtually any kind of tissue in the body. About 1 percent of the iPS cell colonies spontaneously lost their Y chromosome, turning them into “XO” cells. These cells were injected into embryos from donor female mice, and transplanted into surrogate mothers. The mommy mice gave birth to babies carrying one X chromosome from the original male mouse. Once these mice matured, the females were mated with normal male mice. Some of their offspring had genetic contributions from both fathers.