Localisation of the G gamma-, A gamma-, delta- and beta-globin genes on the short arm of human chromosome 11.

Human-mouse somatic cell hybrids have proved invaluable in assigning human genes to their respective human chromosomes. To date, the success of this approach has depended on identifying human proteins which are synthesised in hybrid cells containing a small number of human chromosomes. Consequently, chromosome assignment has been limited mainly to human proteins which are expressed in man-mouse somatic cell hybrids and for which a suitable assay, usually electrophoretic or immunological, exists to distinguish between the human and murine homologous proteins. This technique is therefore unsuitable for the assignment of those human genes which are expressed only in differential cells and not in hybrid cells. Here, we describe how nucleic acid hybridisation and restriction endonuclease mapping of DNA can be combined to test for the presence of human structural gene sequences within hybrid cell DNA. This method can be used to assign any purified human DNA sequence to a human chromosome, and does not require the DNA sequence to be expressed in man-mouse hybrid cells.