CRISPR/Cas9 genome editing technology was used to create a deletion spanning from exon 1 to exon 8. This allele (c.135_1301del1165) forms protein p.A46Tfs14 and is referred to as Espnldelta. No labeling with BG35961 anti-ESPNL antibody was detected in cochlear hair bundles of homozygous mutant mice, indicating that this is a null allele.