Homozygous viable. Nonsense and splicing alleles identified by amplicon sequencing. The gk5241 mutation is C->T, flanking sequences GAGCTTCCACAACGACTCCTCCGACTAGGC and TGAAATTTTAGGGGGTTCTGGGATTGAGGT. The gk5242 mutation is C->T, flanking sequences ACAATATCCCTCTCTCCTCCATCACCACCC and ACTGAGAATTCATCAAATTTTCTTTATTGT.