sentence: The wrd cycG double mutant was molecularly verified by PCR reactions straddling the missing exon 5 in wrd and verifying the additional 350 bp deletion existing in the distal gene copy of cycG .19,30 The following primer pairs were used for the PCR reaction : Wrd KO UP 5 ′ CCT GAG GTC CTC CGG CTA CTT GAT CCT T 3 ′ and Wrd KO LP 5 ′ TCC AAT AGT TGT AAT ACA AAT TGA TGG TCG ATA A 3 ′ as well as HR7 UP 5 ′ ACT CGC CAT GGA CGC CCA CAG CT C 3 ′ and HR7 LP 5 ′ TGG AAC GAG GCC ACG CTC ATG CAG G 3 ′ .