A cre-IRES-VenusGFP cassette followed by SV40 666bp sequence and neomycin cassette flanked by two Frt sites and a loxP site was inserted at ATG of Hoxa13 gene and entire first exon was replaced.F1 offspring were intercrossed with homozygous FLPeR mice to delete the neomycin cassette. (J:181230, J:224090)