A long-range cis-regulatory element for class I odorant receptor genes

Area of Science:

• Genetics
• Neuroscience
• Molecular Biology

Background:

• Olfactory sensory neurons (OSNs) express a single odorant receptor (OR) gene.
• OR genes are categorized into class I and class II, with distinct genomic organizations.

Purpose of the Study:

• To identify regulatory elements controlling class I OR gene expression.
• To investigate the evolutionary conservation and function of these regulatory elements.

Main Methods:

• Identification and characterization of the J element, a conserved enhancer for mouse class I OR genes.
• Analysis of the J element's regulatory range and its role in allelic exclusion.

Main Results:

• The J element is conserved across mammals, from platypus to humans.
• It regulates most class I OR genes over a range of approximately 3 megabases.
• Deletion of the J element increases class I gene expression frequency, demonstrating its role in allelic exclusion.

Conclusions:

• The J element is a long-range cis-regulatory element governing singular class I OR gene expression.
• Phylogenetic preservation of the J element supports the maintenance of single-cluster organization for class I OR genes in mammals.