title: Gene duplication in bacteria: alteration of gene dosage by sister-chromosome exchanges.
mesh_terms: D000483:Alleles; D005796:Genes; D005809:Genes, Regulator; D008040:Genetic Linkage; D006639:Histidine / Q000235:genetics; D009876:Operon; D011995:Recombination, Genetic; D012486:Salmonella typhimurium / Q000235:genetics* / Q000254:growth & development; D012854:Sister Chromatid Exchange
chemical_list: D006639:Histidine