Irradiation microcell-mediated chromosome transfer (XMMCT): the generation of specific chromosomal arm deletions.

The microcell-mediated chromosome transfer technique has been used to introduce whole chromosomes into malignant cells and revert the tumorigenic phenotype. However, in most instances the limited availability of selectable chromosomes has hindered the ability to reduce the region containing the tumor suppressive information. The work presented here describes a new method to enrich for specific chromosomal arm deletions of selectable chromosomes and thereby more finely focus upon the genetic region of interest. The irradiation-microcell mediated chromosome transfer (XMMCT) technique involves the irradiation of microcells containing single human chromosomes followed by fusion to a nonirradiated host and cytogenetic characterization. The XMMCT procedure was performed on a microcell hybrid containing a der(11) as the only human chromosome. The resultant irradiated microcell hybrids were found to have deletions that ranged from simple interstitial deletions to complex deletions/rearrangements involving only the human der(11) chromosome. The XMMCT procedure has broad applications in generating chromosomal reagents for mapping genetic loci and for use in functional analyses such as tumor suppression studies.