An allelic difference determines reciprocal patterns of expression of binding sites for Dolichos biflorus lectin in inbred strains of mice.

We used staining of tissue sections by lectin conjugates to screen inbred strains of mice for polymorphisms which could be used as histological markers of chimaerism. We found one polymorphism, which involves reciprocal patterns of expression of binding sites for the N-acetyl-galactosamine-binding lectins from Dolichos biflorus (DBA), Helix pomatia (HPA) and Wisteria floribunda (WFA) on intestinal epithelium and vascular endothelium. The polymorphism is due to alleles at a single locus, designated D1b-1 (for Dolichos lectin binding). Of 29 inbred strains examined, 3 are D1b-1a (type strain RIII-ro; gut epithelium-ve, vascular endothelium + ve), and 26 are D1b-1b (type strain C57BL/6J; gut epithelium + ve, vascular endothelium-ve). In RIII-ro and C57BL/6J embryos, the polymorphic difference is not clearly present until day 11 of gestation. Before then, embryos of both strains express binding sites on gut epithelium and on endothelium. The temporal and tissue-specific patterns of expression of lectin-binding sites may result from differences in expression of an N-acetyl galactosaminosyl transferase. If so, elucidation of the genetic basis of the polymorphism might provide an insight into the mechanisms of developmental regulation of glycosyltransferase activity.