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Assaying Surface Expression of Chemosensory Receptors in Heterologous Cells
Published on: February 23, 2011
Mutually exclusive expression of odorant receptor transgenes
S Serizawa1, T Ishii, H Nakatani
1Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
Nature Neuroscience
|June 22, 2000
Summary
Researchers studied odorant receptor (OR) gene expression in mice. They found that OR genes are rarely expressed together in single neurons, demonstrating a novel mutually exclusive expression pattern.
Area of Science:
- Genetics
- Neuroscience
- Molecular Biology
Background:
- Odorant receptors (ORs) are crucial for detecting diverse smells.
- OR gene expression is known to be monoallelic, meaning only one allele is expressed.
- The mechanism governing the selection of a single OR gene among many remains an active area of research.
Purpose of the Study:
- To investigate the phenomenon of mutually exclusive expression among non-allelic odorant receptor (OR) genes.
- To determine if OR genes with identical coding and regulatory sequences exhibit mutually exclusive expression.
- To compare this expression pattern to known monoallelic expression in immune system genes.
Main Methods:
- Generation of transgenic mice carrying the murine OR gene MOR28.
- Distinguishing transgene and endogenous MOR28 expression using beta-galactosidase and green fluorescent protein (GFP) markers.
- Double staining of olfactory epithelium to visualize co-expression patterns in individual olfactory neurons.
Main Results:
- Rare co-expression of the transgene and endogenous MOR28 in individual olfactory neurons.
- Similar mutually exclusive expression observed between differently tagged, identical transgenes at the same chromosomal locus.
- This study provides the first evidence of mutually exclusive activation among non-allelic OR gene members.
Conclusions:
- Odorant receptor gene expression exhibits a monoallelic and mutually exclusive pattern, extending beyond allelic inactivation.
- This mode of gene regulation, previously observed only in immune system antigen-receptor genes, is demonstrated in OR gene families.
- Findings suggest a sophisticated regulatory mechanism ensuring the unique identity of olfactory neurons.
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