PATTERNS OF GENE-EXPRESSION ALONG THE CRYPT-VILLUS AXIS IN MOUSE JEJUNAL EPITHELIUM

Background: There is considerable interest in gene expression along th e crypt-villus axis of the small intestinal epithelium, particularly i n the identification of genes expressed in intestinal crypts. Methods: In an attempt to identify crypt-expressed genes, single-stranded cDNA made from normal mouse jejunal epithelium was used in subtractive hyb ridization against single-stranded cDNA from epithelium from which cry pt cells were depleted by 2,000 rads of gamma irradiation. Partial DNA sequence and in situ hybridization of 72 resulting clones were determ ined. Results: The sequence of 45 clones matched previously published genes, Gene expression patterns fell into three categories: expression throughout the crypt-villus axis, expression restricted to the villus , and expression restricted to the crypt. Clones in the first two cate gories could be further divided into three subgroups: those with unifo rm expression, those with an increasing gradient of expression, and th ose with a decreasing gradient of expression along the crypt-villus ax is. Twenty two clones showed a stronger expression in crypt and lower villus cells, four of these were differentially localized to the crypt . Two of the crypt localized clones were uniformly expressed throughou t the crypt, expression of one was stronger in the lower crypt, and ex pression of the remaining clone was enhanced Paneth cells, We report t he full-length cDNA sequence of the Paneth-cell-enhanced clone. Conclu sions: The screen isolated crypt-expressed genes that may prove useful tools in the study of crypt biology. In a companion report, we charac terize one of the crypt clones. (C) 1996 Wiley-Liss, Inc.