Baby monkey is first primate created using sperm from tissue transplanted into dad
"The technique could help boys made infertile by cancer treatment to become fathers later in life."
…Orwig’s team harvested tissue from the testicles of five monkeys — including Grady’s father — when they were too young to produce sperm. They froze the tissue samples until just before the monkeys reached puberty, then thawed the samples and sewed the tissue under the skin on the back and scrotum of the animals.
Less than a year later, the patches of tissue were producing testosterone, and all of the tissue recovered from both graft sites were making sperm. Orwig’s team then took sperm from Grady’s father and used in vitro fertilization to produce an embryo…
(Researchers have previously used the technique to produce babies in mice and pigs.)
https://www.nature.com/articles/d41586-019-00938-9