Soa genotype selectively affects mouse gustatory neural responses to sucrose octaacetate

Area of Science:

• Genetics
• Neuroscience
• Sensory Biology

Background:

• Behavioral acceptance of bitter compounds like sucrose octaacetate (SOA) is influenced by genetic factors.
• Allelic variation in the Soa gene dictates SOA acceptance in mice.
• Congenic mouse strains are valuable tools for mapping gene effects.

Purpose of the Study:

• To investigate the genetic basis of sucrose octaacetate (SOA) avoidance in mice.
• To determine the role of the Soa gene in peripheral taste responsiveness.
• To map the chromosomal location of the Soa gene.

Main Methods:

• Utilized congenic mouse strains (SW.B6-Soa(b)) with defined genetic backgrounds.
• Employed microsatellite markers to map the donor chromosome fragment.
• Assessed behavioral responses to SOA using two-bottle preference tests.
• Measured gustatory nerve responses (chorda tympani and glossopharyngeal) to SOA and other taste stimuli.

Main Results:

• The Soa gene, located on a 5-10 cM fragment of distal chromosome 6, controls SOA avoidance.
• SWR/J mice (SOA tasters) avoided SOA and showed strong gustatory nerve responses.
• SW.B6-Soa(b) mice (SOA non-tasters) were indifferent to SOA and exhibited weak nerve responses.
• No genotype-dependent differences were observed for other taste stimuli (sucrose, NaCl, HCl, quinine, etc.).

Conclusions:

• The Soa genotype critically influences peripheral taste receptor cell responsiveness to SOA.
• Both chorda tympani (CT) and glossopharyngeal (GL) nerves are involved in mediating the Soa gene's effect on SOA taste perception.
• This study elucidates the peripheral mechanisms underlying genetic variation in bitter taste perception.