DLL1 and infection: Six infection schemes were performed according to the aforementioned Notch ligand expression patterns, which included: J1-6d/J1-12d, designed such that cells on day 6/12 of otic progenitor differentiation were infected with JAG-1-shRNA2; J2-5d/D1-5d/J2+D1-5d, designed such that cells on day 5 of hair cell differentiation were infected with JAG-2-shRNA4/DLL-1-shRNA3/JAG-2-shRNA4 + DLL-1-shRNA3.