Phenotypes for Rb1 Tg(Col1a1-cre)1Bek MGI:3574808 MGI Mouse

abnormal organ of Corti supporting cell proliferation ( J:96345 )

• detected many proliferating cochlear supporting cells at E13.5 and E18.5 when these cells are normally postmitotic, indicating that differentiated cells continue to cycle and divide

abnormal organ of Corti morphology ( J:96345 )

• proliferating cells were found in the zone of nonproliferating cells in the primordial organ of Corti at E13.5

increased cochlear hair cell number ( J:96345 )

• increased hair bundle number in E18.5 cochleas with many improperly oriented

• detected many proliferating hair cells at E13.5 and E18.5 when these cells are normally postmitotic, indicating that differentiated cells continue to cycle and divide

increased cochlear inner hair cell number ( J:96345 )

• cochleas had 3-4 rows of inner hair cells compared to one row of inner hair cells in wildtype

increased cochlear outer hair cell number ( J:96345 )

• cochleas had 7-8 rows of outer hair cells compared to 3 rows of outer hair cells in wildtype

increased Deiters cell number ( J:96345 )

• increased ratio of outer hair cells to Deiters' cells, suggesting continous hair cell division

• increased numbers of Deiters' cells, but not pillar cells, than in controls

increased vestibular hair cell number ( J:96345 )

• E18.5 utricles had 40% more cells with bundles

• proliferating hair cells and supporting cells were seen in the utricle at E13.5 and E18.5 when these cells are normally postmitotic, however, cell fate determination and subsequent differentiation was intact in these proliferating cells

• observed hair cells in metaphase in E18.5 utricles

abnormal hearing physiology ( J:96345 )

• transduction currents in ear hair cells were smaller than in controls (10-20 pA versus 200 pA in controls)