Differential expression of the mouse D2 dopamine receptor isoforms

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Dopamine receptors are crucial G protein-coupled receptors involved in various neurological processes.
• The D2 dopamine receptor subtype plays a significant role in motor control, reward, and hormone regulation.

Purpose of the Study:

• To identify and characterize the complementary DNAs (cDNAs) encoding mouse D2 dopamine receptors.
• To investigate the existence and distribution of different D2 dopamine receptor forms in the mouse.
• To assess the functional properties of the identified D2 receptor variants.

Main Methods:

• cDNA identification and characterization.
• Alternative splicing analysis.
• mRNA distribution analysis using Northern blotting or in situ hybridization.
• Radioligand binding assays using [3H]spiperone.

Main Results:

• Two distinct cDNA forms of the mouse D2 dopamine receptor were identified, originating from the same gene via alternative splicing.
• mRNA distribution analysis revealed differential expression patterns, with the larger form being more abundant overall, except in the brain stem where the shorter form predominates.
• Mammalian cells transfected with both D2 receptor forms exhibited high-affinity binding of [3H]spiperone, indicating functional receptor expression.

Conclusions:

• The mouse D2 dopamine receptor exists in at least two isoforms generated by alternative splicing.
• The differential expression of these isoforms suggests region-specific functions within the mouse brain.
• Both D2 receptor forms are functionally expressed and capable of high-affinity ligand binding.