Before revision: Artificial female sperm production Creating female sperm was first raised as a possibility in a patent filed in 1991 by injecting a woman 's cells into a man 's testicles, though the patent focused mostly on injecting altered male cells into a man 's testes ( to correct genetic diseases ) .
After revision: Artificial female sperm production Creating female sperm was first raised as a possibility in a patent filed in 1991 by injecting a female 's cells into a male 's testicles, though the patent focused mostly on injecting altered male cells into a male 's testes to correct genetic diseases .