Phenotypes associated with this allele

• Allele Symbol: Gnat3^tm1Rfm
• Allele Name: targeted mutation 1, Robert F Margolskee
• Allele ID: MGI:2152966
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Gnat3^tm1Rfm/Gnat3^tm1Rfm	involves: 129S1/Sv * C57BL/6J	MGI:3615488
cx2	Gnat1^tm1Clma/Gnat1^tm1Clma Gnat3^tm1Rfm/Gnat3^tm1Rfm	involves: 129S1/Sv * BALB/c * C57BL/6	MGI:3640095

Genotype
MGI:3615488

hm1

• Allelic Composition: Gnat3^tm1Rfm/Gnat3^tm1Rfm
• Genetic Background: involves: 129S1/Sv * C57BL/6J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

taste/olfaction

abnormal taste sensitivity ( J:36885 )

• homozygotes exhibit normal taste epithelia, with no significant differences in the three types of taste papillae, number of taste buds in each papilla or complement of taste receptor cells per bud relative to wild-type mice

• homozygotes display normal responses to a range of salty (NaCl) and sour (HCl) solutions

• notably, although the electrophyiological (chorda tympani) response is greater for sweet than for bitter compounds, the aversive behavioral effect is greater with bitter compounds

abnormal bitter taste sensitivity ( J:36885 )

• homozygotes exhibit reduced aversive behavioral and electrophysiological responses to bitter compounds (denatorium and quinine) relative to wild-type mice

abnormal sweet taste sensitivity ( J:36885 )

• homozygotes also exhibit reduced behavioral and electrophysiological responses to sweet compounds (sucrose and sweetener SC45647) relative to wild-type mice

abnormal umami taste sensitivity ( J:92635 )

• reduced preference for MSG at concentrations normally preferred by control mice

Genotype
MGI:3640095

cx2

• Allelic Composition: Gnat1^tm1Clma/Gnat1^tm1Clma; Gnat3^tm1Rfm/Gnat3^tm1Rfm
• Genetic Background: involves: 129S1/Sv * BALB/c * C57BL/6

taste/olfaction

abnormal umami taste sensitivity ( J:92635 )

• loss of sensitivity to umami taste sensation as indicated by indifference to MSG at concentrations preferred by control mice

• in contrast, mice homozygous only for Gnat3^tm1Rfm continue to be sensitive to MSG but at a reduced level

nervous system

abnormal somatic nervous system physiology ( J:92635 )

• response to MSG stimulation in the corda tympani is reduced

• MSG response in the glossopharyngeal nerve is normal