The Epimorphin Gene Is Highly Conserved among Humans, Mice, and Rats and Maps to Human Chromosome 7, Mouse Chromosome 5, and Rat Chromosome 12

A genomic DNA fragment containing the rat epimorphin gene sequence was cloned from a rat DNA cosmid library using a mouse epimorphin cDNA probe. Within the cosmid insert, nine epimorphin exons were identified and sequenced. The predicted amino acid sequence of the rat epimorphin protein exhibited 96 and 86% identity with the mouse and human epimorphin proteins, respectively. Consistent with the developmentally related expression pattern of the mouse epimorphin gene, transcripts of the rat epimorphin gene were detected in 17-day postfertilization rat embryos. The gene, designatedEpim,was assigned to rat chromosome 12 by somatic cell hybrid analysis and localized to 12q16 by fluorescencein situhybridization. The mouse and human homologs of this gene were localized on mouse chromosome 5 and human chromosome 7 by linkage analysis and chromosomalin situhybridization, respectively.