All Phenotypes Atp6v1b1<vtx> MGI Mouse

decreased urine calcium level ( J:243701 )

• Background Sensitivity: while potassium, sodium and chloride concentrations in urine are normal, homozygotes have decreased calcium in the urine with an approximately 70% decrease on the MRL/MpJ background (45.9 +/- 6.01 mg/g versus 163.3 +/- 17.4 mg/g in the wild-type control) and this difference is less severe on the C57BL/6J background

decreased urine calcium level ( J:243701 )

• Background Sensitivity: while potassium, sodium and chloride concentrations in urine are normal, homozygotes have decreased calcium in the urine with an approximately 70% decrease on the MRL/MpJ background (45.9 +/- 6.01 mg/g versus 163.3 +/- 17.4 mg/g in the wild-type control) and this difference is less severe on the C57BL/6J background

abnormal cochlea morphology ( J:243701 )

• Background Sensitivity: the boney interscalar septum between the lower cochlear base and lower apical turn is frequently absent

abnormal Reissner membrane morphology ( J:243701 )

• Background Sensitivity: as part of the abnormal histology, the attachment point can be displaced to the medial side of the elongated spiral limbus

small scala tympani ( J:243701 )

abnormal spiral limbus morphology ( J:243701 )

• stubby and misshapen with few fibrocytes, especially apically

abnormal membranous labyrinth morphology ( J:243701 )

• Background Sensitivity: at embryonic day 15 the membranous labyrinth is dilated relative to that found in heterozygotes or homozygotes on a C57BL/6J background, and this enlargement is more pronounced at birth and the swelling of the endolymphatic sac and duct as well as the utricle, saccule and cochlear duct is apparent

abnormal organ of Corti morphology ( J:243701 )

• Background Sensitivity: lateral expansion of fluid spaces with basal displacement of the organ of Corti

decreased cochlear outer hair cell number ( J:243701 )

• Background Sensitivity: outer hair cells absent in the chochlear base but mostly present in the apex

abnormal spiral ligament fibrocyte morphology ( J:243701 )

• Background Sensitivity: extremely thin throughout the cochlea and Type I and III fibrocytes are almost entirely missing behind the stria

abnormal type I spiral ligament fibrocytes ( J:243701 )

abnormal type III spiral ligament fibrocytes ( J:243701 )

thin spiral ligament ( J:243701 )

dilated scala media ( J:243701 )

dilated endolymphatic duct ( J:243701 )

decreased otolith number ( J:243701 )

• Background Sensitivity: cleared whole mounts of the inner ear from P1 pups shows only a few widely dispersed otoconial crystals, and the few otoconia that adults have are very large and mis-shaped, tending toward triangular shapes, and in 5 of 9 homozygotes these large otoconia were found in scala media, but in heterozygotes or C57BL/6J homozygotes there are only normal appearing otoconia in both the utricle and saccule

abnormal cochlear endolymph ionic homeostasis ( J:243701 )

• resulting in increased endolymph volume

decreased endocochlear potential ( J:243701 )

• Background Sensitivity: EP nearly absent in homozygotes on the MRL/MpJ background assessed between 2.5 and 4.5 months of age, although heterozygotes on the MRL/MpJ background and homozygotes on the C57BL/6J congenic background are normal

increased or absent threshold for auditory brainstem response ( J:243701 )

• Background Sensitivity: on the MRL/MpJ background homozygotes assessed between 4 and 6 weeks of age display no or almost no response at 8, 16, or 32 kHz, between 2.5 and 4.5 months of age fail to elicit an ABR even at 100 dB SPL, but heterozygotes do not display this deafness and homozygotes on a C57BL/6J congenic background also do not display this deafness

head tilt ( J:243701 )

• Background Sensitivity: variable head tilting on the MRL/MpJ background but not found on the C57BL/6J background

bidirectional circling ( J:243701 )

• Background Sensitivity: on the MRL/MpJ background but not the C57BL/6J background