The human MUC4 gene encodes a large membrane-associated mucin, characterized by a mucin tandem repeat domain and a growth factor-like transmembrane domain. In addition to the originally published sequence (sv0-MUC4), several MUC4 cDNA sequences (called sv1-MUC4 to sv21MUC4, MUC4/X, MUC4/Y) from various tissues and cell lines have been recently described. They differ from sv0MUC4 by deletions and/or insertions located in the 3¢ region or, for two of them, by deletion of the central repetitive domain. To establish the nature of the mechanisms responsible for the diversity of MUC4 transcripts, the genomic structure of the 3¢ region of the human MUC4 gene.
