Genomic structure and chromosomal mapping of the human and mouse hippocalcin genes

In an attempt to elucidate the possible relationship of hippocalcin to neur ological disorders, we isolated and analyzed the human and mouse hippocalci n genes. The human and mouse hippocalcin genes contain three exons and two introns, and span approximately 7 and 8 kb, respectively. The exon/intron s plice junctions of the human and mouse genes are all situated in exactly th e same position and are not consistently placed with respect to the coding regions of the tandemly repeated EF-hand motifs. The amino acid sequences o f human and mouse hippocalcins deduced from the genes are 100% identical. W ithin the 2-kb 3'-flanking sequences of the human and mouse genes, one cons erved polyadenylation signal was identified at positions 762 and 823 bp dow nstream from TAG, respectively. Within the 2.6-kb 5'-flanking sequences of the human and mouse genes, neither a canonical 'TATA' box nor a 'CAAT' box was found. Southern blot analysis of the human and mouse genomic DNAs demon strated that the positive bands coincide exactly with those expected from t he sequence of the cloned genes, indicating that the human and mouse hippoc alcin genes are present as a single-copy gene. Fluorescence in-situ hybridi zation revealed that the human hippocalcin gene is located at chromosome 1 p34.2-35 and the mouse hippocalcin gene at chromosome 4 D2-D3. (C) 1998 Els evier Science B.V. All rights reserved.