Transforming growth factor beta gene maps to human chromosome 19 long arm and to mouse chromosome 7.

Transforming growth factors (TGF) are defined as biologically active polypeptides which reversibly confer the transformed phenotype onto untransformed cultured cells. They have been subdivided into two classes: type alpha and type beta TGFs. TGF-beta acts synergistically with TGF-alpha in inducing phenotypic transformation. TGF-beta can also act as a negative autocrine growth factor. A human 1050-bp EcoRi cDNA fragment was used to map the human locus for TGF-beta by Southern blotting of DNA prepared from 17 human X Chinese hamster somatic cell hybrids. The human-specific restriction fragments segregated with human chromosome 19 in all of 14 informative hybrids. All other human chromosomes were discordant with the TGF-beta bands in at least four hybrids. After in situ hybridization of the tritiated TGF-beta probe to normal human metaphase spreads, 151 silver grains were scored in 54 cells. Of 24 grains over chromosome 19, 16 grains (11%) lay over region 19q13.1----q13.3. Of the 54 cells analyzed, 16 (30%) had label over region 19q13.1----q13.3. Thus, TGFB is assigned to chromosome 19, subbands q13.1----q13.3. The Tgf-beta locus in the mouse was mapped to chromosome 7 by hybridizing a murine cDNA probe to a Chinese hamster X mouse hybrid panel. Human chromosome 19 and proximal mouse chromosome 7 share another four homologous loci.