Human gene mapping using an X/autosome translocation

Abstract

Human fibroblasts containing a translocation between the X chromosome and chromosome 15 were fused with the 6-thioguanine-resistant mouse cell line, IR. Resulting hybrids, selected in HAT medium, retained the X/15 chromosome. Hybrids which were counterselected in 6-thioguanine lost this chromosome. The X-linked markers glucose-6-phosphate dehydrogenase (G6PD), phosphoglycerate kinase (PGK), and hypoxanthine phosphoribosyl transferase (HPRT), and the non-X-linked markers pyruvate kinase (PK_M2) mannose phosphate isomerase (MPI), N-acetyl hexosaminidase A (HEX_A) and β₂-microglubulin (β₂-m) all segregated in concordance with the X/15 translocation chromosome. The latter markers have been assigned to chromosome 15. Selection against the X/15 chromosome was done using antihuman β₂-m serum. Electrophoretic and immunochemical analyses of the N-acetyl hexosaminidases A and B in these hybrids were performed.