title: Insertion of drug resistance genes in animals.
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002875:Chromosomes / Q000502:physiology; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial; D005796:Genes; D005818:Genetic Engineering; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells; D008727:Methotrexate / Q000494:pharmacology*; D051379:Mice; D008845:Microinjections; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate