with one parent.
German developmental biologist Karl
working with Peter Hoppe at Jackson Laboratory in Maine,
created mice with only a single parent. Illmensee and
Hoppe grew mice with only a father as well as mice with
only a mother.
Just after fertilization, the genes of the father and mother are separated, and make up two different pronuclei in the egg cell. Illmensee removed one of these pronuclei from a fertilized mouse egg, and then used special enzymes to duplicate the remaining pronuclei. As a result of this process, the egg now carried the genes of only one of its parents.
Illmensee and Hoppe claimed to have created five fatherless and two motherless mice from their experiments. However, the validity of this experiment was later questioned by Illmensee and Hoppe's colleagues following suspicious laboratory activity by Illmensee.