FISH mapping of BAC probes containing the Smn andNaip genes to mouse Chromosome 13. The BAC genetic markerD13Mit300 was used as a hybridization probe to identify mouse Chromosome 13 accurately (D. Noya, X.-N. Chen, B. Birren, K. Devon, J.S. Lee, and J.R. Korenberg, unpubl.). The map assignment was corroborated by chromomycin A3 and distamycin A reverse banding. The differentially labeled Smn (digoxigenin; red signal) andNaip (biotinylated; green signal) probes were cohybridized onto metaphase chromosomes and unstimulated interphase cells prepared from strain 129. The FITC and rhodamine signals were mapped to the region MMU13D1-2.1. The MGD accession number for physical mapping ofSmn and Naip is MGD-INEX-31. It should be noted that multiple copies of a region-specific repeat that contains at leastNaip exon 5 was not resolved by FISH because of the size of the BAC used as probe for the Naip gene.
