Method for producing non-human large mammal or fish each capable of producing gamete originated from different individual

A method for producing a non-human large mammal or fish that produces gametes originating in a second non-human large mammal or fish, said method comprising

• transplanting at least one blastomere derived from the second non-human large mammal or fish as a donor cell into an embryo derived from a first non-human large mammal or fish, said embryo being at a cleavage stage and having a genome in which a function of nanos3 gene is inhibited, to prepare a chimeric embryo between the first non-human large mammal and the second non-human large mammal or between the first fish and the second fish, and
• allowing said chimeric embryo to develop into an individual,
• wherein in the transplanting step, no other donor cells than said at least one blastomere are transplanted into said embryo.