{"doi":"10.1073/pnas.86.24.9951","title":"Cytochemical observation of regulated bacterial beta-galactosidase gene expression in mammalian cells.","abstract":"<jats:p>Bacterial beta-galactosidase, encoded by the lacZ gene, serves as a sensitive cytochemical marker in eukaryotic cells and tissues. In transient expression experiments, human and simian cells stain blue 48 hr after transfection with a plasmid containing a lacZ gene, whose expression is directed by a simian virus 40 promoter containing a synthetic lactose operator sequence. Transfection efficiency was about 0.6%. Incorporation of an operator sequence within the promoter permits regulation of beta-galactosidase gene expression by the lacI gene product, the lac repressor. When cells were cotransfected with the lacZ plasmid and a second plasmid containing the lacI gene, beta-galactosidase activity was extinguished. Its activity could be reestablished to original levels upon application of isopropyl beta-D-thiogalactoside to transfected cells. A cell line that stably carries both the lacI and lacZ genes was efficiently induced to synthesize beta-galactosidase after isopropyl beta-D-thiogalactoside administration. In transient expression experiments and in stably transfected lines, repression and induction of beta-galactosidase activity were predominantly at the transcriptional level.</jats:p>","journal":"Proceedings of the National Academy of Sciences","year":1989,"id":40479,"datarank":1.1640688584387997,"base_score":3.044522437723423,"endowment":3.044522437723423,"self_citation_contribution":0.4566783656585135,"citation_network_contribution":0.7073904927802862,"self_endowment_contribution":0.4566783656585135,"citer_contribution":0.7073904927802862,"corpus_percentile":null,"corpus_rank":null,"citation_count":20,"citer_count":16,"citers_with_citation_signal":12,"citers_with_endowment":12,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":196600,"name":"E S Feliciano","orcid":null,"position":1,"is_corresponding":false},{"id":196601,"name":"P J Stambrook","orcid":null,"position":2,"is_corresponding":false},{"id":196599,"name":"H S Liu","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"base_score":3.044522437723423,"endowment":3.044522437723423,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"2481319","pmcid":"PMC298620","openalex_id":"https://openalex.org/W2023049163","authors":[],"funders":[{"funder_name":"NCI NIH HHS","grant_id":"CA-36897","title":null},{"funder_name":"NCI NIH HHS","grant_id":"CA-48118","title":null}],"total_grants":2,"fwci":1.626,"citation_percentile":0.842391,"influential_citations":0,"citation_trend":[{"year":2014,"count":1},{"year":2019,"count":1},{"year":2020,"count":1},{"year":2021,"count":1}],"oa_status":"green","license":null,"oa_locations":[{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/298620","host_type":"repository"},{"url":"https://doi.org/10.1073/pnas.86.24.9951","host_type":"BRONZE"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/298620","host_type":"repository"},{"url":"https://pnas.org/doi/pdf/10.1073/pnas.86.24.9951","host_type":"publisher"},{"url":"https://pubmed.ncbi.nlm.nih.gov/2481319","host_type":"repository"},{"url":"http://europepmc.org/articles/PMC298620","host_type":"repository"}],"fields_of_study":["Animal Genetics and Reproduction","CRISPR and Genetic Engineering","Virus-based gene therapy research","Biology","Medicine","Animals","Blotting, Northern","Cell Line","Enzyme Induction","Enzyme Repression","Galactosidases","Gene Expression Regulation, Enzymologic","Genes, Bacterial","Genetic Vectors","Humans","RNA, Bacterial","Transcription, Genetic","Transfection","beta-Galactosidase"],"mesh_terms":["Animals","beta-Galactosidase","Cell Line","Enzyme Induction","Enzyme Repression","Galactosidases","Genes, Bacterial","Genetic Vectors","Humans","RNA, Bacterial","Transcription, Genetic","Transfection","Blotting, Northern","Gene Expression Regulation, Enzymologic"],"keywords":["Lac repressor","Molecular biology","lac operon","Transfection","Beta-galactosidase","Plasmid","Biology","Expression vector","Repressor","Gene expression","Gene","Reporter gene","Regulation of gene expression","Cell culture","Biochemistry","Recombinant DNA","Genetics"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-06-12T06:33:08.630863Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}