Quantitative PCR analysis of Olfrs and OMP.

<p>Corneal RNA was isolated and subjected to qPCR as described in Materials and Methods. PCR products for <i>Gapdh</i> and <i>Omp</i>, become detectable at earlier PCR cycles than products for genes expressed at lower levels, such as <i>Olfr543</i>, <i>Olfr1444</i> and <i>Olfr558</i>. Note that qPCR curves for <i>Olfr543</i> and <i>Chrm3</i> are virtually identical, suggesting that Olfr543 and M3-muscarinic receptor are expressed at similar levels in the cornea. When PCR primers were located within a single exon (<i>Gapdh</i> and <i>Olfr558</i>, Fig. 3B) PCR products were detected even in the absence of the RT reaction. However, they were detected at much later cycles compared to the reactions with the RT step, thus, contributing less than 2% to the total PCR product.