All Phenotypes Slc19a2<tm1Ejn> MGI Mouse

increased susceptibility to induced morbidity/mortality ( J:101675 )

• on a diet containing 1.25 mg/kg or no thiamine homozygotes become extremely ill within 3-4 weeks or 17-18 days, respectively, with signs of illness appearing earlier than in wild-type mice

azoospermia ( J:101675 )

• on either a thiamine replete or deficient diet no mature spermatocytes are found and degenerating germ cell are seen

• on a thiamine deficient diet many seminiferous tubules contain only Sertoli cells

arrest of male meiosis ( J:101675 )

• germ cells progress to the pachytene stage but no haploid spermatids are found

small testis ( J:101675 )

• on a normal diet testis size is about 65-75% smaller than wild-type

• reduced testis size is more severe on a thiamine deficient diet

male infertility ( J:101675 )

• males, but not females, are infertile

abnormal erythropoiesis ( J:101675 )

• after 2 weeks on a thiamine deficient diet, the number of pronormoblasts in homozygotes is decreased >10-fold and the number of basophilic normoblasts is decreased from 8.9% to 1.1% relative to wild-type mice

• however, no ringed sideroblasts are seen with Perl's Prussian blue staining nor iron granules are seen in circulating red blood cells

decreased erythrocyte cell number ( J:101675 )

• after 2 weeks on a thiamine deficient diet, homozygotes develop decreased red cell counts

• however, on a thiamine replete diet hematological parameters and blood glucose are normal

thrombocytosis ( J:101675 )

• after 2 weeks on a thiamine deficient diet homozygotes develop a slight but significant increase in platelet numbers

small testis ( J:101675 )

• on a normal diet testis size is about 65-75% smaller than wild-type

• reduced testis size is more severe on a thiamine deficient diet

cochlear inner hair cell degeneration ( J:118928 )

• by 19 days on a low thiamine diet, homozygotes exhibit progressive IHC loss in the apical half of the cochlea

• by 26 days on a low thiamine diet, IHC loss is nearly complete throughout most of the mid-cochlear region, while the basal 1/3 of the cochlea remains intact

• by 36 days, slight extension of IHC loss is noted in the basal cochlear extreme

cochlear outer hair cell degeneration ( J:118928 )

• by 36 days on a low thiamine diet, homozygotes exhibit extensive OHC loss

• OHC loss progresses at a significantly slower rate than IHC loss which rises between 19 and 26 days after the onset of a low thiamine diet

increased or absent threshold for auditory brainstem response ( J:118928 )

• after 11 days on a low-thiamine diet (2 vs. 22 mg/kg in normal chow), homozygotes show elevated ABR thresholds by ~40 dB esp. for frequencies <22 kHz, whereas wild-type mice display no threshold elevations, even after 26 days

• after 26 days on a low-thiamine diet, homozygotes exhibit ABR threshold shifts of ~50 dB at 11.3 and 16 kHz

• on a low-thiamine diet, mutant ABR wave 1 latencies remain normal even when thresholds are elevated by 30-40 dB

• only partial recovery of ABR thresholds is observed after reintroduction of thiamin to a low-thiamine diet for 19 days

• on a normal thiamine diet or a thiamine-enriched diet (3 mg/kg), homozygotes show no significant ABR threshold differences relative to wild-type, even at >70 days on the diet

abnormal distortion product otoacoustic emission ( J:118928 )

• after 26 days on a low-thiamine diet, homozygotes exhibit DPOAE shifts of 10-20 dB relative to wild-type mice

• DPOAE shifts are smaller than the shifts observed in ABR thresholds

• however, on a normal thiamine diet or a thiamine-enriched diet (3 mg/kg), homozygotes show no significant DPOAE threshold differences relative to wild-type, even at >70 days on the diet

sensorineural hearing loss ( J:118928 )

• homozygotes display a rare form of sensorineural hearing loss, with selective IHC loss after 1-2 weeks on a low thiamine diet, and significantly greater IHC than OHC loss after prolonged thiamine deprivation