Possible non-functional crypts in small intestine defined using mouse aggregation chimaeras.

We have identified a minor population of crypts in small intestine which do not appear to export cells to villi. These crypts can be observed in whole-mounts of small intestine prepared from C57BL/6J<-->SWR mouse aggregation chimaeras stained with a peroxidase conjugate of the lectin Dolichos biflorus agglutinin (DBA-Px). In preparations where by chance the C57BL/6J epithelium (positive staining) forms only a minor component of the chimaera, occasional crypts occur which are isolated from larger patches of C57BL/6J epithelium and are surrounded by SWR (non-staining) epithelium. Fifty-one of 383 isolated C57BL/6J crypts (13%) did not appear to export cells to villi, although the crypt mouth is surrounded by a small patch of C57BL/6J epithelium on the intervillus gut floor.