The paper says > Using immature oocytes with a deletion of the H19 imprinted region, Kono et al. (2004) produced the first mice from two mothers [...] bipatern

The paper says > Using immature oocytes with a deletion of the H19 imprinted region, Kono et al. (2004) produced the first mice from two mothers [...] bipaternal reproduction, which has only been found in specific fish (Corley-Smith et al., 1996), has not been achieved in mammals until now. so I guess a mouse with two mothers existed before, and they now also made a mouse with two fathers.