{"doi":"10.1126/science.275.5305.1485","title":"A Plastid of Probable Green Algal Origin in Apicomplexan Parasites","abstract":"<jats:p>\n            Protozoan parasites of the phylum Apicomplexa contain three genetic elements: the nuclear and mitochondrial genomes characteristic of virtually all eukaryotic cells and a 35-kilobase circular extrachromosomal DNA. In situ hybridization techniques were used to localize the 35-kilobase DNA of\n            <jats:italic>Toxoplasma gondii</jats:italic>\n            to a discrete organelle surrounded by four membranes. Phylogenetic analysis of the\n            <jats:italic>tufA</jats:italic>\n            gene encoded by the 35-kilobase genomes of coccidians\n            <jats:italic>T. gondii</jats:italic>\n            and\n            <jats:italic>Eimeria tenella</jats:italic>\n            and the malaria parasite\n            <jats:italic>Plasmodium falciparum</jats:italic>\n            grouped this organellar genome with cyanobacteria and plastids, showing consistent clustering with green algal plastids. Taken together, these observations indicate that the Apicomplexa acquired a plastid by secondary endosymbiosis, probably from a green alga.\n          </jats:p>","journal":"Science","year":1997,"id":635727,"datarank":0.9959813750739805,"base_score":6.639875833826536,"endowment":6.639875833826536,"self_citation_contribution":0.9959813750739805,"citation_network_contribution":0.0,"self_endowment_contribution":0.9959813750739805,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":764,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":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":1649451,"name":"Charles F. Delwiche","orcid":null,"position":1,"is_corresponding":false},{"id":768445,"name":"Paul W. Denny","orcid":null,"position":2,"is_corresponding":false},{"id":1649453,"name":"Lewis G. Tilney","orcid":null,"position":3,"is_corresponding":false},{"id":543908,"name":"Paul Webster","orcid":"0000-0002-1980-6931","position":4,"is_corresponding":false},{"id":1649456,"name":"R. J. M. Wilson","orcid":null,"position":5,"is_corresponding":false},{"id":1649457,"name":"Jeffrey D. Palmer","orcid":null,"position":6,"is_corresponding":false},{"id":299002,"name":"David S. Roos","orcid":"0000-0001-6725-4089","position":7,"is_corresponding":false},{"id":34875,"name":"Sabine Köhler","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"A Plastid of Probable Green Algal Origin in Apicomplexan Parasites","abstract":"<jats:p>\n            Protozoan parasites of the phylum Apicomplexa contain three genetic elements: the nuclear and mitochondrial genomes characteristic of virtually all eukaryotic cells and a 35-kilobase circular extrachromosomal DNA. In situ hybridization techniques were used to localize the 35-kilobase DNA of\n            <jats:italic>Toxoplasma gondii</jats:italic>\n            to a discrete organelle surrounded by four membranes. Phylogenetic analysis of the\n            <jats:italic>tufA</jats:italic>\n            gene encoded by the 35-kilobase genomes of coccidians\n            <jats:italic>T. gondii</jats:italic>\n            and\n            <jats:italic>Eimeria tenella</jats:italic>\n            and the malaria parasite\n            <jats:italic>Plasmodium falciparum</jats:italic>\n            grouped this organellar genome with cyanobacteria and plastids, showing consistent clustering with green algal plastids. Taken together, these observations indicate that the Apicomplexa acquired a plastid by secondary endosymbiosis, probably from a green alga.\n          </jats:p>","is_dataset_classified":null,"base_score":6.639875833826536,"endowment":6.639875833826536,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"9045615","pmcid":null,"openalex_id":"https://openalex.org/W2030773468","authors":[],"funders":[{"funder_name":"NIAID NIH HHS","grant_id":"AI-31808","title":null},{"funder_name":"Medical Research Council","grant_id":"MC_U117532072","title":null},{"funder_name":"NIGMS NIH HHS","grant_id":"GM-52857","title":null}],"total_grants":3,"fwci":28.9907,"citation_percentile":0.99973133,"influential_citations":0,"citation_trend":[{"year":2012,"count":30},{"year":2013,"count":27},{"year":2014,"count":28},{"year":2015,"count":12},{"year":2016,"count":19},{"year":2017,"count":18},{"year":2018,"count":21},{"year":2019,"count":15},{"year":2020,"count":16},{"year":2021,"count":10},{"year":2022,"count":18},{"year":2023,"count":7},{"year":2024,"count":29},{"year":2025,"count":17},{"year":2026,"count":5}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://www.science.org/doi/pdf/10.1126/science.275.5305.1485","host_type":"publisher"},{"url":"https://doi.org/10.1126/science.275.5305.1485","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/9045615","host_type":"repository"}],"fields_of_study":["Parasitic Infections and Diagnostics","Toxoplasma gondii Research Studies","Coccidia and coccidiosis research","Animals","Apicomplexa","Chlorophyta","DNA, Circular","DNA, Protozoan","Eimeria tenella","In Situ Hybridization","Intracellular Membranes","Microscopy, Electron","Molecular Sequence Data","Peptide Elongation Factor Tu","Phylogeny","Plasmodium falciparum","Plastids","Symbiosis","Toxoplasma"],"mesh_terms":["Chlorophyta","Animals","DNA, Circular","Intracellular Membranes","Microscopy, Electron","Molecular Sequence Data","Peptide Elongation Factor Tu","Phylogeny","Plasmodium falciparum","Symbiosis","Toxoplasma","DNA, Protozoan","Apicomplexa","Eimeria tenella","In Situ Hybridization","Plastids"],"keywords":["Plastid","Apicoplast","Biology","Apicomplexa","Endosymbiosis","Genome","Extrachromosomal DNA","Plasmodium falciparum","Protozoa","Phylogenetic tree","Plasmodium (life cycle)","Genetics","Organelle","Gene","Parasite hosting","Chloroplast","Malaria"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-06T15:30:06.275393Z","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":[]}