Fuss Stefan H, Omura Masayo, Mombaerts Peter
The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Cell. 2007 Jul 27;130(2):373-84. doi: 10.1016/j.cell.2007.06.023.
From the approximately 1,200 odorant receptor (OR) genes in the mouse genome, an olfactory sensory neuron is thought to express only one gene. The mechanisms of OR gene choice are not understood. A 2.1 kilobase region (the H element) adjacent to a cluster of seven OR genes has been proposed as a trans- and pan-enhancer for OR gene expression. Here, we deleted the H element by gene targeting in mice. The deletion abolishes expression of a family of three OR genes proximal to H, and H operates in cis on these genes. Deletion of H has a graded effect on expression of a distal group of four OR genes, commensurate with genomic distance. There is no demonstrable effect on expression of OR genes located outside the cluster. Our findings are not consistent with the hypothesis of H as an essential trans-acting enhancer for genome-wide regulation of OR gene expression.
在小鼠基因组中大约1200个嗅觉受体（OR）基因中，一个嗅觉感觉神经元被认为只表达一个基因。OR基因选择的机制尚不清楚。与一组七个OR基因相邻的一个2.1千碱基区域（H元件）已被提出作为OR基因表达的反式和泛增强子。在这里，我们通过基因打靶在小鼠中删除了H元件。该缺失消除了H近端三个OR基因家族的表达，并且H对这些基因顺式起作用。H的缺失对远端四个OR基因的表达有分级影响，与基因组距离相称。对位于该基因簇之外的OR基因的表达没有明显影响。我们的发现与H作为OR基因表达全基因组调控的必需反式作用增强子的假设不一致。
