The present invention relates to a method for producing a homozygous non-human organism from a heterozygous non-human organism, which homozygous organism can be crossed to obtain a hybrid, comprising providing a heterozygous starting organism; allowing the organism to produce SDR-0 cells through meiosis, which cells originate from second division restitution; regenerating SDR-0 organisms from the SDR-0 cells; and producing the homozygous organism from the SDR-0 organisms thus obtained. The invention further relates to a method for producing a hybrid, comprising crossing a first homozygous organism that is produced according to the above method with a second homozygous organism. Furthermore, the invention provides homozygous non-human organism and hybrid non-human organisms obtainable by these methods.