The insertion of Velocigene cassette ZEN-Ub1 created a deletion of size 2000bp between positions 103790086-103792085 of Chromosome 7 (Build GRCm39). Exon 2 was replaced with a lacZ reporter and a floxed neomycin resistance cassette. qRT-PCR and Western blot analysis confirmed complete loss of mRNA and protein expression in the testes of adult homozygotes.