Assignment of the human MARS gene, encoding methioninyl-tRNA synthetase, to chromosome 12 using human X Chinese hamster cell hybrids.
We have isolated interspecific somatic cell hybrids between a temperature-sensitive Chinese hamster ovary (CHO) cell methioninyl -tRNA synthetase mutant and human peripheral leukocytes. The hybrids were selected at 39 degrees C which requires the retention and expression of the human gene, MARS , which complements the defective CHO gene. In vitro heat-inactivation experiments on the methioninyl -tRNA synthetase activity in cell-free extracts from heat-resistant hybrids indicate that the human form of this enzyme and, therefore, the human MARS gene is present in hybrid cells. Cytogenetic analysis of three independent temperature-resistant hybrids revealed the presence of a single human chromosome, number 12. Two other independent hybrids examined contained human chromosome 12 as well as a second human chromosome. Electrophoretic analysis of extracts from hybrid cell lines for a human chromosome 12 marker isozyme, LDH-B, showed a pattern of heterotetrameric bands consistent with the presence of the human form of this enzyme in these cells. The correlation between the presence of the human form of methioninyl -tRNA synthetase and human chromosome 12 in temperature-resistant hybrids indicates that the human MARS locus is located on this chromosome.
D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002906:Chromosomes, Human, 6-12 and X; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D005796:Genes; D006801:Humans; D006822:Hybrid Cells / Q000502:physiology; D007527:Isoenzymes; D007621:Karyotyping; D007770:L-Lactate Dehydrogenase / Q000235:genetics; D008718:Methionine-tRNA Ligase / Q000235:genetics*; D009154:Mutation; D010053:Ovary
D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D000604:Amino Acyl-tRNA Synthetases; D008718:Methionine-tRNA Ligase