Cryptdin gene expression in developing mouse small intestine

oping mouse small intestine. Am. J. PhysioZ. 272 (Gastro-intest. Liver PhysioZ. 35): Gl97-G206, 1997.-In rodents, the four intestinal epithelial cell lineages differentiate and be-come morphologically distinct during the first 2-3 postnatal wk. In studies reported here, reverse transcriptase-polymer-ase chain reaction (RT-PCR)-based assays detected Paneth cell defensin mRNAs in intestinal RNA from l-day-old (Pl) mice before crypt formation and maturation of the epithe-lium. Analysis of these defensin-coding RT-PCR products from Pl mice showed that 69 % of clones sequenced coded for cryptdin-6, suggesting that it is the most abundant enteric defensin mRNA in the newborn. Paneth cell mRNAs, includ-ing cryptdins- and-5, lysozyme, matrilysin, and defensin-related sequences, also were detected in RNA from Pl mouse intestine. Unlike adult mice, where only Paneth cells ar