Cystic fibrosis: from linked markers to the gene

SV40-mediated tumor selection and chromosome transfer to enrich for cystic fibrosis region

The somatic cell hybrid C121, with chromosome 7 as its sole human component, arose when mouse macrophages SV40 genomes are integrated at 7q31-7q35. We show that hybrids with a reduced chromosome 7 component, but which retain markers linked to the cystic fibrosis locus, can be generated by direct in vivo tumor selection or following chromosome-mediated gene transfer and SV40-mediated cellular transformation. Our methods for chromosome fragmentation and fine-structure mapping can now be applied to the substantial number of SV40-transformed human cell lines, with independent chromosomal integration sites, already available. Our results also suggest that expression of human epidermal growth factor receptor augments the tumorigenic potential of the SV40-transformed C121 hybrid.

Recombinant DNA and the major psychiatric disorders

The two major psychiatric disorders, schizophrenia and the major affective disorders are among the most common genetic conditions in man. The precise biochemical defects which cause these disorders are unknown. This article reviews the new recombinant DNA techniques and their application to date in attempting to locate the genes responsible for these disorders. As has been demonstrated for other genetic conditions, these techniques may help to elucidate the biochemical defects which lead to the development of the more genetic forms of these psychiatric illnesses.