Partial deletion of the bovine ED1 gene causes anhidrotic ectodermal dysplasia in cattle

Anhidrotic ectodermal dysplasia (EDI) is characterized by hypotrichosis, re duced number of sweat glands, and incisior anodontia in human, mouse, and c attle. In affected humans and mice, mutations in the EDI gene coding for ec todysplasin I are found. Ectodysplasin I is a novel trimeric transmembrane protein with an extracellular TNF-like signaling domain that is believed to be involved in the formation of hair follicles and tooth buds during fetal development. We report the construction of a 480-kb BAC contig harboring t he complete bovine EDI gene on BTA Xq22-Xq24. Physical mapping and sequence analysis of the coding parts of the EDI gene revealed that a large genomic region including exon 3 of the EDI gene is deleted in cattle with anhidrot ic ectodermal dysplasia in a family of German Holstein cattle with three af fected maternal half sibs.