Genetic characterization of the murine Ym1 gene and identification of a cluster of highly homologous genes

The murine Ym1 gene belongs to a family of mammalian genes that are homolog ous to the chitinases from lower organisms, such as insects, nematodes, bac teria, and plants. All of these homologous mammalian proteins (except one m ember) have no demonstrable chitinase activity and therefore cannot be cons idered chitinases. The biological functions of these proteins remain unknow n. However, these proteins may function through binding to carbohydrate pol ymers. In an effort to characterize the murine Ym1 gene better, we have del ineated its genomic structure. We mapped the chromosomal location of the Ym 1 gene to a central region of mouse chromosome 3 (in the region syntenic to human chromosome 1p13) and that of another murine chitinase-like gene, Brp 39, to a central region of mouse chromosome 1 (in the region syntenic to hu man chromosome 1q31). In addition, we identified several genes highly homol ogous to Ym1 that cluster at the Ym1 locus. We show that these genes are ex pressed selectively in different mouse tissues. (C) 1998 Academic Press.