MAPPING OF AN ORDERED SET OF 14 COSMIDS TO HUMAN-CHROMOSOME-12P BY 2-COLOR IN-SITU HYBRIDIZATION

To map human chromosome 12p aberrations by fluorescence in situ hybrid ization (FISH), cosmids were isolated or obtained for 14 known 12p loc i (D12S119, D12S158, D12S178, D12S370, D12S380E, A2M, CACNL1A1, FGF6, GAPD, KRAS2, PRB1, PZP, TPI1, and VWF). Using two-color FISH with thre e labeled probes to interphase nuclei, and to prometaphase chromosomes where possible, the order of these loci was sequentially determined t o be -GAPD-TPI1-A2M-PZP-PRB1-D12S178-D12S119-KRAS2-cen. Two cell lines were analyzed with this set of cosmids. The EBV-transformed cell line TA carries a der(12) with a deletion of bands 12p13.1-->p11.2. D12S17 8, D12S119, and KRAS2 were absent in the der(12), whereas the other lo ci were present. The second cell. line, GM01203A, exhibits a balanced t(4;12)(4q25; 12p13.3)with a breakpoint between FGF6 and D128370.