Here is the context of the Mitf129 mutant allele, as determined by PCR and Sanger sequencing: ACCGACTGTTAACAAGAATGTTTTCTTACTGGACCAAACAGAATATATCAAGCTCAGTAG ATGGAAAAAAGATGGACAAAGTTTCTACCATGAGAAAAAAAAATTCAACAAAAGTTAAAA TGGAGAAAAAAGAAACAGTTGTACCGATTACAGAAATGCGTGCTCTGGAATTTCAAG <Mitf129 CRISPR deletion> atattgagttataaatgataaagttgttaaaattcgatataatttctttgaggaattatgtta aattctacaaggcttaaaaggtccatcctttttatagtttgtcaaactcagtgaacttaa aataacatgctcttttatatgtatagaccgtattttttcaattcatactattgattcact