Tissue print hybridization. A simple technique for detecting organ- and tissue-specific gene expression.

We have used a new technique, which we call tissue print hybridization, to monitor organ- and tissue-specific expression of auxin-induced RNAs in soybean (Glycine max cv. Wayne) seedlings. This technique is modified from that originally published by Cassab and Varner (J Cell Biol 105: 2581-2588, 1987) for the localization of extensin protein in soybean seed using an antibody probe. We extended this original tissue print procedure by utilizing(35)S-labeled antisense RNAs for localization of specific RNAs immobilized on nylon membranes. We also employed modifications to improve the resolution of the autoradiographic images. We have used this technique to demonstrate the tissue-specific expression of auxin-regulated genes in elongating hypocotyl regions of etiolated soybean seedlings and the rapid turn-over of RNAs encoded by these genes during gravistimulation.