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 α and type β TGFs. TGF-β acts synergistically with TGF-α in inducing phenotypic transformation. TGF-β can also act as negative autocrine growth factor. A human 1050-bp EcoRI cDNA fragment was used to map the human locus for TGF-β by Southern blotting of DNA prepared from 17 human × Chinese hamster somatic cell hybrids. The humanspecific restriction fragments segregated with human chromosome 19 in all of 14 informative hybrids. All other human chromosomes were discordant with the TGF-β bands in at least four hybrids. After in situ hybridization of the tritiated TGF-β 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. TheTgf- β locus in the mouse was mapped to chromosome 7 by hybridizing a murine cDNA probe to a Chinese hamster × mouse hybrid panel. Human chromosome 19 and proximal mouse chromosome 7 share another four homologous loci.

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

Human probes identifying the cellular homologs of the v-ets gene, Hu-ets-1 and Hu-ets-2, and two panels of rodent-human cell hybrids were used to study specific translocations occurring in acute leukemias. The human ets-1 gene was found to translocate from chromosome 11 to 4 in the t(4;11)(q21;23), a translocation characteristic of a subtype of leukemia that represents the expansion of a myeloid/lymphoid precursor cell. Similarly, the human ets-2 gene was found to translocate from chromosome 21 to chromosome 8 in the t(8;21)(q22;q22), a nonrandom translocation commonly found in patients with acute myeloid leukemia with morphology M2 (AML-M2). Both translocations are associated with expression different from the expression in normal lymphoid cells of ets genes, raising the possibility that these genes play a role in the pathogenesis of these leukemias.

http://science.sciencemag.org/content/sci/231/4736/379.full.pdf

Hu-ets-1 and Hu-ets-2 genes are transposed in acute leukemias with (4;11) and 8;21) translocations

EMR1, an unusual member in the family of hormone receptors with seven transmembrane segments.

The tissue distribution of different glutathione S-transferases (GST) is analysed by electrophoresis.

Human genes for glutathione S-transferases

Extracts of hamster-human and mouse-human hybrids, some with translocations involving chromosome 19, have been assayed for both human spleen ferritin (rich in L subunits) and human heart ferritin (rich in H subunits). Hybrid lines retaining part of the long arm of chromosome 19 including the region 19q13.3→19qter produced human “L” type ferritin. This confirms the previous assignment of the “ferritin gene” to chromosome 19 (Caskey et al. 1983). However, lines retaining chromosome 11 were found to contain human “H” type ferritin suggesting that the gene for the “H” subunit is on this chromosome. The presence of chromosome 6 was not necessary for the expression of either “H” or “L” type human ferritin. It thus seems unlikely that the gene for idiopathic haemochromatosis is a ferritin gene.

Assignment of human ferritin genes to chromosomes 11 and 19q13.3----19qter.

Techniques are described for the electrophoretic characterization on Cellogel of adenosine deaminase, adenylate kinase, enolase, fumarase, α-galactosidase, glucosephosphate isomerase, glutathione reductase, glutamic-oxaloacetic transaminase, guanylate kinase, hexosaminidase, hypoxanthine-guanine phosphoribosyltransferase, indophenol oxidase, “malic” enzyme, mannosephosphate isomerase, nucleoside phosphorylase, peptidase-A, peptidase-B, peptidase-C, phosphoglucomutase, pyruvate kinase, triosephosphate isomerase, and UDP glucose pyrophosphorylase1 in the man-Chinese hamster somatic cell hybrid systems.

Margy Vervloet

Papers

Enzyme electrophoresis on cellulose acetate gel. ii. zymogram patterns in man-chinese hamster somatic cell hybrids