Donor construct for gene targeting at the ry locus. A 4.16kb segment of the ry gene, in which the zinc finger nuclease (ZFN) recognition site which is recognised by Zzzz\ZFNhs.ryA and Zzzz\ZFNhs.ryB in combination has been replaced by two in-frame stop codons and a XbaI site. The ry sequence is flanked by FRT and RS(I-SceI) sites.