Table 1.

Inner ear defects in Eya1 and Six1 heterozygous embryos

Six1+/−n=22 (11)Eya1+/−n=22 (11)Six1+/−/Eya1+/−n=40 (20)
Abnormalitiesn%n%n%
Endolymphatic duct (truncated)2 (2)9.1 (18.2)3 (2)13.6 (18.2)5 (4)12.5 (20)
Endolymphatic sac (absent or mal-shaped)5 (3)22.7 (27.3)8 (5)36.4 (45.5)15 (9)37.5 (45)
Saccule (malformed)4 (3)18.2 (27.3)007 (5)17.5 (25)
Posterior ampulla (absent)00007 (5)17.5 (25)
Posterior semicircular canal (absent or truncated)00007 (5)17.5 (25)
Cochlea* (shortened)4 (3)18.2 (27.3)4 (4)18.2 (36.4)19 (13)47.5 (65)
  • n, number of ears (the numbers shown in parentheses are the numbers of embryos).

    %, the percentage of the ears or the embryos (shown in the parentheses) that showed defects.

  • * Four out of 22 Six1+/− 129 ears (3 of 11 embryos) showed slightly shortened cochlea at E16.5, three completed near 1.5 turns and one completed between 1 and 1.25 turns instead of 1.75 turns (Fig. 8B). Similarly, four out of 22 Eya1+/− 129 ears (4 of 11 embryos) showed slightly shortened cochlea, two reached near 1.5 turns and the other two coiled between 1 and 1.25 turns at E16.5. By contrast, 19 of 40 Eya1/Six1 129 compound heterozygous ears (13 out of 20 embryos) showed severely affected cochlea with abnormal distal tips. Among the 19 affected cochlea, 16 completed less than one turn and three coiled between 1 and 1.25 turns.