GENETIC AND PHYSICAL MAPPING OF HUMAN RECOVERIN - A GENE EXPRESSED INRETINAL PHOTORECEPTORS

Purpose. Recoverin is a calcium-binding protein that may be involved i n phototransduction in mammalian retinal photoreceptors, and is consid ered to be a candidate gene for retinitis pigmentosa. This study was u ndertaken to develop the recoverin locus into a polymorphic marker for future linkage studies on retinitis pigmentosa families. Methods. A h uman genomic cosmid clone was isolated and used to map the recoverin g ene to a human chromosome through hybridization to a panel of somatic hybrid cell line DNAs, and to human metaphase chromosomes by fluoresce nce in situ hybridization. A dinucleotide repeat polymorphism located within the coding region of the recoverin gene was identified, and use d to genetically map the recoverin gene relative to index markers. In addition, three restriction fragment length polymorphisms revealed by the cosmid clone were identified and characterized. Results. Hybridiza tion to the somatic hybrid eel line DNAs localized the recoverin gene to chromosome 17. Recoverin was further localized to 17p12-p13 by fluo rescence in situ hybridization. The dinucleotide repeat polymorphism a nd restriction fragment length polymerphisms at the recoverin locus ha ve a cumulative polymorphic information content = 0.71. Conclusions. T hese polymorphic markers and additional closely linked markers will be useful for linkage analysis of families with retinitis pigmentosa.