[Localization of epidermal growth factor and nerve growth factor mRNAs in mouse submandibular gland by a simplified in situ hybridization with riboprobes].

We simplified procedures of in situ hybridization with riboprobes on serial sections of paraffin-embedded tissues. We found that when tissues were fixed with 4% paraformaldehyde, embedded in paraffin, and cut serial sections with 5 microns thick, excellent results were obtained without proteolytic, heat, or HCl treatment. With our simplified method, both EGF and NGF mRNAs were detected intensively and specifically in granular convoluted tubule (GCT) cells of a male mouse submandibular gland, but not detected in either the acini or ducts other than the GCT. Accumulation of the silver grains was localized in the basal side of the GCT cells. No significant hybridization was observed in those cells with the sense probe and in the parotid and sublingual gland even with the anti-sense probe. Since our results were not only very consistent with other data, but also much more excellent than other results obtained by in situ hybridization on the similar tissues, our simplified method should be very useful to study gene expression on tissue sections.