title: Isozyme studies on the association of the herpes simplex virus type 1 thymidine kinase gene with human chromosomes in somatic cell hybrids.
abstract: To investigate chromosomal site(s) of integration of the herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) gene in biochemically transformed [HeLa(BU25)/KOS 8-1] cells, these human cells which had been transformed by ultraviolet light-irradiated HSV-1 were fused with TK-negative mouse LM(TK-) cells, human-mouse somatic cell hybrid clones (LH81 clones 1-20) were isolated by HATG-ouabain selection and their chromosomes and isozymes were analyzed. Electrophoretic and serological analyses showed that all 20 clones expressed type-specific HSV-1 TK. Isozyme analyses on 29 gene-enzyme systems representing 22 human chromosomes revealed that all of the HSV-1 TK-positive clones expressed human aminoacylase-1 (ACY-1) and esterase D (ESD), which have been mapped to human chromosomes 3 and 13, respectively. Other human isozymes were detected in only one to four clones or in none of the clones. Chromosome analyses showed that: (1) the hybrid clones retained only a few human chromosomes; (2) a marker chromosome, designated M7, consisting of a chromosome 17 translocated to the short arm of chromosome 3, occurred in 36 out of the 41 metaphases examined of LH81-4 clones 1 to 4 and in 31 out of the 33 metaphases examined of LH81-12 clone 10; (3) a modified M7 chromosome, (M7/m), in which the distal 2/3 of the long arm of M7 was translocated to a small acrocentric mouse chromosome, was the only human chromosome found in metaphases of LH81-13 clone 17; and (4) an intact human chromosome 13 was not present in LH81-12 clone 10 or LH81-13 clone 17 cells. Counterselection with BrdUrd resulted in the isolation of subclones lacking HSV-1 TK, human ACY-1 and ESD, and the human marker M7 chromosomes. The experiments indicate that the HSV-1 TK gene is probably associated in HeLa (BU25)/KOS 8-1 cells with marker chromosome M7, but the possibility is not excluded that the segment of human chromosome 13 which codes for ESD is involved.
mesh_terms: D000581:Amidohydrolases / Q000235:genetics; D000818:Animals; D002874:Chromosome Mapping; D002999:Clone Cells; D004950:Esterases / Q000235:genetics; D005814:Genes, Viral; D006367:HeLa Cells / Q000201:enzymology; D006801:Humans; D006822:Hybrid Cells / Q000201:enzymology*; D007527:Isoenzymes / Q000235:genetics*; D008677:Metaphase; D051379:Mice; D018139:Simplexvirus / Q000235:genetics*; D013937:Thymidine Kinase / Q000235:genetics*; D014178:Translocation, Genetic
chemical_list: D007527:Isoenzymes; D013937:Thymidine Kinase; D004950:Esterases; D000581:Amidohydrolases