Chromosomal localization of the CKβ8-1/CKβ8 gene. (A) Genomic Southern blots revealed that the genes encoding Lkn-1 and CKβ8-1/CKβ8 are single copy, but related genes. Twenty micrograms of genomic DNA prepared from a melanoma cell line (OCM1) and two B-cell lymphoma cell lines (GM02430 and GM03365) were digested withHindIII and were transferred to a nylon filter membrane. The Lkn-1 or CKβ8-1 probe was hybridized to the membrane, which was finally washed with 2 × SSC at 65°C for 30 minutes. Indicated by arrows are the genes encoding Lkn-1 and CKβ8-1/CKβ8. (B) The genes encoding Lkn-1 and CKβ8-1/CKβ8 are located at the same chromosome. Three BAC clones (9-0-20, 23-1-14, 110-F-8) were isolated and 1 μg of each DNA was digested with HindIII. Southern blot was performed as described above.