The purpose of this project is to develop methods for gene transfer to mammalian cells and to use these techniques for gene mapping, analysis of gene expression, and cloning eukaryotic genes. Many independent somatic cell hybrid lines segrating human chromosomes have been isolated and the human chromosome content of each line determined. Analysis of these lines with isotopically labeled cloned DNA probes has previously allowed assignment to specific human chromosomes, and sometimes regional localization, of human cellular onc genes, immunoglobulin genes and pseudogenes, alpha, beta, and gamma fibrinogen genes, members of the metallothionein multigene family, and calcitonin. Similar procedures have been used to localize other human genes including cytochrome P1-450 to chromosome 15, L-myc to chromosome 1 p, follicular lymphoma breakpoint to chromosome 18, and a gene and pseudogene for J protein to chromosome 4 and 8, respectively. Other human genes which have been chromosomally and regionally mapped by both somatic cell hybrid and in situ chromosome hybridization techniques are p53 tumor antigen (chromosome 17p13), collagen type III (chromosome 2q11-13), and beta polymerase (chromosome 8q24). In a second area of investigation, rearrangements of cellular protooncogenes have not been detected in guinea pig leukemia. Evaluation of c-abl in guinea pig leukemia by cloning, chromosomal mapping, and expression is in progress.