{"gene":"MEI1","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2002,"finding":"MEI1 (mouse) is required for homologous chromosome synapsis during meiosis I; mei1/mei1 spermatocytes arrest at zygotene with failure of RAD51 to associate with meiotic chromosomes despite evidence of chromosomal breaks, indicating a defect upstream of RAD51 loading.","method":"Forward genetic screen in mice; immunofluorescence for RAD51 on meiotic chromosomes; meiotic stage-specific gene expression analysis","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct loss-of-function mouse model with defined cellular phenotype (zygotene arrest, RAD51 failure), replicated in subsequent studies","pmids":["11820814"],"is_preprint":false},{"year":2003,"finding":"MEI1 is required for genetically programmed DNA double-strand break (DSB) formation during meiotic leptonema; Mei1 mutant spermatocytes show greatly reduced γH2AX at leptonema (comparable to Spo11-null mice), and cisplatin treatment of mutant males restores RAD51 loading, demonstrating intact recombinational repair machinery but defective DSB induction.","method":"Positional cloning; cisplatin rescue experiment in mutant spermatocytes; immunofluorescence for γH2AX and RAD51; comparison with Spo11-null controls","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (γH2AX quantification, cisplatin rescue, Spo11 comparison) in single rigorous study; replicated in epistasis study","pmids":["14668445"],"is_preprint":false},{"year":2005,"finding":"Genetic epistasis places MEI1 upstream of DMC1 in the meiotic recombination pathway; double-mutant (Mei1−/−; Dmc1−/−) mice phenocopy Mei1−/− single mutants in both sexes, confirming MEI1 acts before DSB repair by homologous recombination.","method":"Double-mutant analysis (Mei1−/−; Dmc1−/−) with phenotypic comparison of spermatogenesis and oogenesis","journal":"Chromosoma","confidence":"High","confidence_rationale":"Tier 2 / Strong — classical genetic epistasis with reciprocal sex phenotype analysis; direct test of pathway order","pmids":["15928951"],"is_preprint":false},{"year":2023,"finding":"Human MEI1 protein physically interacts with key meiotic DSB-promoting complex proteins ANKRD31, IHO1, REC114, and MEI4; pathogenic biallelic variants in patients with NOA disrupt these interactions.","method":"Co-immunoprecipitation assays with wild-type and mutant MEI1 constructs","journal":"Journal of human genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — co-IP demonstrated interaction with four partners, single lab, no reciprocal pulldown or structural validation reported in abstract","pmids":["36759719","41706353"],"is_preprint":false},{"year":2021,"finding":"Protein-truncating and missense mutations in MEI1 reduce MEI1 protein levels, while splicing mutations cause abnormal alternative splicing; demonstrated by western blotting and minigene analysis in vitro.","method":"Western blotting; minigene splicing assay in vitro","journal":"Human reproduction (Oxford, England)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — two orthogonal methods (western blot + minigene) in single lab establishing molecular consequence of mutations","pmids":["34037756"],"is_preprint":false},{"year":2025,"finding":"A homozygous whole-exon deletion of exon 19 in MEI1 produces a truncated MEI1 protein with premature termination at exon 20; embryos from affected individuals show high rates of aneuploidy.","method":"Whole-exome sequencing, Sanger sequencing, cDNA amplification/sequencing, western blotting, immunofluorescence, preimplantation genetic testing by whole-genome sequencing","journal":"Reproductive sciences (Thousand Oaks, Calif.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (WB, IF, cDNA sequencing) in single lab confirming truncated protein production","pmids":["40164922"],"is_preprint":false},{"year":2025,"finding":"Biallelic MEI1 variants causing embryonic arrest do not alter the subcellular localization of MEI1 but significantly reduce its mRNA and protein expression levels.","method":"Western blotting, RT-qPCR, immunofluorescence in HEK293T cells transfected with mutant constructs","journal":"Journal of assisted reproduction and genetics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, overexpression in non-physiological cell line (HEK293T), no functional rescue experiment","pmids":["41315153"],"is_preprint":false},{"year":2015,"finding":"Bovine Mei1 promoter and gene body DNA methylation inversely correlates with Mei1 expression; treatment of bovine mammary epithelial cells with the DNA methyltransferase inhibitor 5-Aza-CdR activates Mei1 expression, indicating that DNA methylation represses Mei1 transcription.","method":"Bisulfite sequencing of promoter/gene body; 5-Aza-CdR treatment; real-time PCR","journal":"Gene","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, pharmacological inhibitor (not specific to Mei1), non-meiotic cell type used","pmids":["26165450"],"is_preprint":false}],"current_model":"MEI1 is a vertebrate-specific meiotic protein required for the formation of programmed DNA double-strand breaks (DSBs) at the initiation of meiotic recombination; it acts upstream of DSB-repair factors (RAD51, DMC1) and physically interacts with the pre-DSB complex proteins ANKRD31, IHO1, REC114, and MEI4, with loss-of-function causing meiotic arrest at zygotene, failure of RAD51 loading onto chromosomes, and sterility in both sexes."},"narrative":{"mechanistic_narrative":"MEI1 is a meiotic protein required for the formation of programmed DNA double-strand breaks (DSBs) that initiate meiotic recombination [PMID:14668445]. Mouse loss-of-function mutants arrest at zygotene with failure of RAD51 to load onto meiotic chromosomes [PMID:11820814], and reduced γH2AX at leptonema comparable to Spo11-null mice identifies a defect in DSB induction rather than in the downstream repair machinery, since cisplatin-induced breaks restore RAD51 loading in mutant spermatocytes [PMID:14668445]. Genetic epistasis places MEI1 upstream of DMC1, confirming it acts before homologous recombination-mediated DSB repair [PMID:15928951]. Mechanistically, human MEI1 physically interacts with the DSB-promoting complex proteins ANKRD31, IHO1, REC114, and MEI4, and pathogenic biallelic variants disrupt these interactions [PMID:36759719, PMID:41706353]. In humans, biallelic MEI1 variants cause infertility through reduced protein levels, aberrant splicing, and protein truncation [PMID:34037756, PMID:40164922], with patient embryos showing high rates of aneuploidy [PMID:40164922].","teleology":[{"year":2002,"claim":"Established that MEI1 is required for homologous chromosome synapsis and acts upstream of RAD51 loading, framing it as an early meiotic factor rather than a repair protein.","evidence":"Forward genetic mouse screen with RAD51 immunofluorescence on meiotic chromosomes","pmids":["11820814"],"confidence":"High","gaps":["Did not define the molecular step MEI1 controls","No biochemical activity or partner identified"]},{"year":2003,"claim":"Pinpointed the defect to programmed DSB formation itself, distinguishing MEI1 from the recombinational repair machinery.","evidence":"Positional cloning, γH2AX quantification, cisplatin rescue, and comparison with Spo11-null spermatocytes","pmids":["14668445"],"confidence":"High","gaps":["Did not show how MEI1 promotes DSB formation mechanistically","Relationship to the Spo11 cleavage machinery left undefined"]},{"year":2005,"claim":"Ordered MEI1 upstream of DMC1 in the recombination pathway via epistasis, confirming it acts before DSB repair in both sexes.","evidence":"Mei1−/−; Dmc1−/− double-mutant phenotypic analysis of spermatogenesis and oogenesis","pmids":["15928951"],"confidence":"High","gaps":["Genetic order does not reveal direct molecular partners","No physical interaction tested"]},{"year":2021,"claim":"Connected human MEI1 mutations to infertility by defining their molecular consequences on protein level and splicing.","evidence":"Western blotting and minigene splicing assays of patient variants in vitro","pmids":["34037756"],"confidence":"Medium","gaps":["In vitro consequences not linked to meiotic phenotype in patient germ cells","No functional rescue"]},{"year":2023,"claim":"Provided the first physical-interaction basis for MEI1 function by linking it to the pre-DSB complex and showing patient variants disrupt these contacts.","evidence":"Co-immunoprecipitation of wild-type and mutant MEI1 with ANKRD31, IHO1, REC114, MEI4","pmids":["36759719","41706353"],"confidence":"Medium","gaps":["Single lab, no reciprocal pulldown or structural validation","Stoichiometry and direct versus indirect binding undefined"]},{"year":2025,"claim":"Extended the phenotypic consequence to human embryos, linking a truncating MEI1 deletion to aneuploidy.","evidence":"Whole-exome/cDNA sequencing, western blot, immunofluorescence, and preimplantation genetic testing","pmids":["40164922","41315153"],"confidence":"Medium","gaps":["Causal mechanism from truncated protein to aneuploidy not established","Localization data from overexpression in non-meiotic cell line"]},{"year":null,"claim":"The biochemical activity by which MEI1 promotes DSB formation and its precise role within the pre-DSB complex remain undefined.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of MEI1 or its complex","No defined enzymatic or scaffolding activity","Direct versus indirect role in Spo11-mediated cleavage unresolved"]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,1,2,5]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,1,2]}],"complexes":[],"partners":["ANKRD31","IHO1","REC114","MEI4"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5TIA1","full_name":"Meiosis inhibitor protein 1","aliases":["Meiosis defective protein 1"],"length_aa":1274,"mass_kda":141.2,"function":"Required for normal meiotic chromosome synapsis. May be involved in the formation of meiotic double-strand breaks (DSBs) in spermatocytes (By similarity)","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/Q5TIA1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MEI1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MEI1","total_profiled":1310},"omim":[{"mim_id":"618431","title":"HYDATIDIFORM MOLE, RECURRENT, 3; HYDM3","url":"https://www.omim.org/entry/618431"},{"mim_id":"608797","title":"MEIOTIC DOUBLE-STRANDED BREAK FORMATION PROTEIN 1; MEI1","url":"https://www.omim.org/entry/608797"},{"mim_id":"605114","title":"SPO11 INITIATOR OF MEIOTIC DOUBLE-STRANDED BREAKS; SPO11","url":"https://www.omim.org/entry/605114"},{"mim_id":"603171","title":"NEURAL PRECURSOR CELL EXPRESSED, DEVELOPMENTALLY DOWNREGULATED 8; NEDD8","url":"https://www.omim.org/entry/603171"},{"mim_id":"231090","title":"HYDATIDIFORM MOLE, RECURRENT, 1; HYDM1","url":"https://www.omim.org/entry/231090"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":20.7},{"tissue":"testis","ntpm":36.6}],"url":"https://www.proteinatlas.org/search/MEI1"},"hgnc":{"alias_symbol":["MGC40042","SPATA38"],"prev_symbol":[]},"alphafold":{"accession":"Q5TIA1","domains":[{"cath_id":"-","chopping":"1169-1246","consensus_level":"medium","plddt":77.4112,"start":1169,"end":1246},{"cath_id":"1.25.40","chopping":"414-475_493-526_537-588","consensus_level":"medium","plddt":90.6471,"start":414,"end":588},{"cath_id":"1.25.10","chopping":"810-817_826-1031_1066-1076","consensus_level":"medium","plddt":80.44,"start":810,"end":1076}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5TIA1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5TIA1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5TIA1-F1-predicted_aligned_error_v6.png","plddt_mean":83.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MEI1","jax_strain_url":"https://www.jax.org/strain/search?query=MEI1"},"sequence":{"accession":"Q5TIA1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5TIA1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5TIA1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5TIA1"}},"corpus_meta":[{"pmid":"11820814","id":"PMC_11820814","title":"The mouse meiotic mutation mei1 disrupts chromosome synapsis with sexually dimorphic consequences for meiotic progression.","date":"2002","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/11820814","citation_count":121,"is_preprint":false},{"pmid":"14668445","id":"PMC_14668445","title":"Positional cloning and characterization of Mei1, a vertebrate-specific gene required for normal meiotic chromosome synapsis in mice.","date":"2003","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/14668445","citation_count":108,"is_preprint":false},{"pmid":"8150281","id":"PMC_8150281","title":"mei-1, a gene required for meiotic spindle formation in Caenorhabditis elegans, is a member of a family of ATPases.","date":"1994","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/8150281","citation_count":88,"is_preprint":false},{"pmid":"8027178","id":"PMC_8027178","title":"Localization of the mei-1 gene product of Caenorhaditis elegans, a meiotic-specific spindle component.","date":"1994","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8027178","citation_count":80,"is_preprint":false},{"pmid":"15928951","id":"PMC_15928951","title":"Mei1 is epistatic to Dmc1 during mouse meiosis.","date":"2005","source":"Chromosoma","url":"https://pubmed.ncbi.nlm.nih.gov/15928951","citation_count":58,"is_preprint":false},{"pmid":"29659827","id":"PMC_29659827","title":"A MEI1 homozygous missense mutation associated with meiotic arrest in a consanguineous family.","date":"2018","source":"Human reproduction (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/29659827","citation_count":52,"is_preprint":false},{"pmid":"9725834","id":"PMC_9725834","title":"Genetic and molecular characterization of the caenorhabditis elegans gene, mel-26, a postmeiotic negative regulator of mei-1, a meiotic-specific spindle component.","date":"1998","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/9725834","citation_count":51,"is_preprint":false},{"pmid":"16683055","id":"PMC_16683055","title":"Polymorphic alleles of the human MEI1 gene are associated with human azoospermia by meiotic arrest.","date":"2006","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/16683055","citation_count":49,"is_preprint":false},{"pmid":"8514128","id":"PMC_8514128","title":"Genetic studies of mei-1 gene activity during the transition from meiosis to mitosis in Caenorhabditis elegans.","date":"1993","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/8514128","citation_count":39,"is_preprint":false},{"pmid":"34037756","id":"PMC_34037756","title":"Novel biallelic mutations in MEI1: expanding the phenotypic spectrum to human embryonic arrest and recurrent implantation failure.","date":"2021","source":"Human reproduction (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/34037756","citation_count":33,"is_preprint":false},{"pmid":"17069791","id":"PMC_17069791","title":"The C. elegans anaphase promoting complex and MBK-2/DYRK kinase act redundantly with CUL-3/MEL-26 ubiquitin ligase to degrade MEI-1 microtubule-severing activity after meiosis.","date":"2006","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/17069791","citation_count":33,"is_preprint":false},{"pmid":"22621901","id":"PMC_22621901","title":"UNC-89 (obscurin) binds to MEL-26, a BTB-domain protein, and affects the function of MEI-1 (katanin) in striated muscle of Caenorhabditis elegans.","date":"2012","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/22621901","citation_count":32,"is_preprint":false},{"pmid":"26165450","id":"PMC_26165450","title":"Molecular characterization and epigenetic regulation of Mei1 in cattle and cattle-yak.","date":"2015","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/26165450","citation_count":20,"is_preprint":false},{"pmid":"23918937","id":"PMC_23918937","title":"Microtubule severing by the katanin complex is activated by PPFR-1-dependent MEI-1 dephosphorylation.","date":"2013","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/23918937","citation_count":19,"is_preprint":false},{"pmid":"36759719","id":"PMC_36759719","title":"Bi-allelic MEI1 variants cause meiosis arrest and non-obstructive azoospermia.","date":"2023","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36759719","citation_count":17,"is_preprint":false},{"pmid":"35596132","id":"PMC_35596132","title":"Recombination rates in pigs differ between breeds, sexes and individuals, and are associated with the RNF212, SYCP2, PRDM7, MEI1 and MSH4 loci.","date":"2022","source":"Genetics, selection, evolution : GSE","url":"https://pubmed.ncbi.nlm.nih.gov/35596132","citation_count":14,"is_preprint":false},{"pmid":"38416203","id":"PMC_38416203","title":"Novel MEI1 mutations cause chromosomal and DNA methylation abnormalities leading to embryonic arrest and implantation failure.","date":"2024","source":"Molecular genetics and genomics : MGG","url":"https://pubmed.ncbi.nlm.nih.gov/38416203","citation_count":7,"is_preprint":false},{"pmid":"40164922","id":"PMC_40164922","title":"Identification of the novel homozygous whole exon deletion in MEI1 underlying azoospermia and embryonic arrest in one consanguineous family.","date":"2025","source":"Reproductive sciences (Thousand Oaks, Calif.)","url":"https://pubmed.ncbi.nlm.nih.gov/40164922","citation_count":1,"is_preprint":false},{"pmid":"41444636","id":"PMC_41444636","title":"Novel biallelic MEI1 variants cause female infertility characterized by multiple pronuclei formation and aberrant embryonic development.","date":"2025","source":"Journal of ovarian research","url":"https://pubmed.ncbi.nlm.nih.gov/41444636","citation_count":0,"is_preprint":false},{"pmid":"41375492","id":"PMC_41375492","title":"The Impact of MEI1 Alternative Splicing Events on Spermatogenesis in Mongolian Horses.","date":"2025","source":"Animals : an open access journal from MDPI","url":"https://pubmed.ncbi.nlm.nih.gov/41375492","citation_count":0,"is_preprint":false},{"pmid":"41315153","id":"PMC_41315153","title":"Novel variants in MEI1 cause female infertility characterized by early embryonic arrest and implantation failure.","date":"2025","source":"Journal of assisted reproduction and genetics","url":"https://pubmed.ncbi.nlm.nih.gov/41315153","citation_count":0,"is_preprint":false},{"pmid":"41706353","id":"PMC_41706353","title":"A common cause of non-obstructive azoospermia: biallelic MEI1 variants and implications for infertility diagnostics.","date":"2026","source":"Journal of assisted reproduction and genetics","url":"https://pubmed.ncbi.nlm.nih.gov/41706353","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13517,"output_tokens":1857,"usd":0.034203,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8779,"output_tokens":1915,"usd":0.045885,"stage2_stop_reason":"end_turn"},"total_usd":0.080088,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"MEI1 (mouse) is required for homologous chromosome synapsis during meiosis I; mei1/mei1 spermatocytes arrest at zygotene with failure of RAD51 to associate with meiotic chromosomes despite evidence of chromosomal breaks, indicating a defect upstream of RAD51 loading.\",\n      \"method\": \"Forward genetic screen in mice; immunofluorescence for RAD51 on meiotic chromosomes; meiotic stage-specific gene expression analysis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct loss-of-function mouse model with defined cellular phenotype (zygotene arrest, RAD51 failure), replicated in subsequent studies\",\n      \"pmids\": [\"11820814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"MEI1 is required for genetically programmed DNA double-strand break (DSB) formation during meiotic leptonema; Mei1 mutant spermatocytes show greatly reduced γH2AX at leptonema (comparable to Spo11-null mice), and cisplatin treatment of mutant males restores RAD51 loading, demonstrating intact recombinational repair machinery but defective DSB induction.\",\n      \"method\": \"Positional cloning; cisplatin rescue experiment in mutant spermatocytes; immunofluorescence for γH2AX and RAD51; comparison with Spo11-null controls\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (γH2AX quantification, cisplatin rescue, Spo11 comparison) in single rigorous study; replicated in epistasis study\",\n      \"pmids\": [\"14668445\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Genetic epistasis places MEI1 upstream of DMC1 in the meiotic recombination pathway; double-mutant (Mei1−/−; Dmc1−/−) mice phenocopy Mei1−/− single mutants in both sexes, confirming MEI1 acts before DSB repair by homologous recombination.\",\n      \"method\": \"Double-mutant analysis (Mei1−/−; Dmc1−/−) with phenotypic comparison of spermatogenesis and oogenesis\",\n      \"journal\": \"Chromosoma\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — classical genetic epistasis with reciprocal sex phenotype analysis; direct test of pathway order\",\n      \"pmids\": [\"15928951\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Human MEI1 protein physically interacts with key meiotic DSB-promoting complex proteins ANKRD31, IHO1, REC114, and MEI4; pathogenic biallelic variants in patients with NOA disrupt these interactions.\",\n      \"method\": \"Co-immunoprecipitation assays with wild-type and mutant MEI1 constructs\",\n      \"journal\": \"Journal of human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — co-IP demonstrated interaction with four partners, single lab, no reciprocal pulldown or structural validation reported in abstract\",\n      \"pmids\": [\"36759719\", \"41706353\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Protein-truncating and missense mutations in MEI1 reduce MEI1 protein levels, while splicing mutations cause abnormal alternative splicing; demonstrated by western blotting and minigene analysis in vitro.\",\n      \"method\": \"Western blotting; minigene splicing assay in vitro\",\n      \"journal\": \"Human reproduction (Oxford, England)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — two orthogonal methods (western blot + minigene) in single lab establishing molecular consequence of mutations\",\n      \"pmids\": [\"34037756\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"A homozygous whole-exon deletion of exon 19 in MEI1 produces a truncated MEI1 protein with premature termination at exon 20; embryos from affected individuals show high rates of aneuploidy.\",\n      \"method\": \"Whole-exome sequencing, Sanger sequencing, cDNA amplification/sequencing, western blotting, immunofluorescence, preimplantation genetic testing by whole-genome sequencing\",\n      \"journal\": \"Reproductive sciences (Thousand Oaks, Calif.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (WB, IF, cDNA sequencing) in single lab confirming truncated protein production\",\n      \"pmids\": [\"40164922\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Biallelic MEI1 variants causing embryonic arrest do not alter the subcellular localization of MEI1 but significantly reduce its mRNA and protein expression levels.\",\n      \"method\": \"Western blotting, RT-qPCR, immunofluorescence in HEK293T cells transfected with mutant constructs\",\n      \"journal\": \"Journal of assisted reproduction and genetics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, overexpression in non-physiological cell line (HEK293T), no functional rescue experiment\",\n      \"pmids\": [\"41315153\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Bovine Mei1 promoter and gene body DNA methylation inversely correlates with Mei1 expression; treatment of bovine mammary epithelial cells with the DNA methyltransferase inhibitor 5-Aza-CdR activates Mei1 expression, indicating that DNA methylation represses Mei1 transcription.\",\n      \"method\": \"Bisulfite sequencing of promoter/gene body; 5-Aza-CdR treatment; real-time PCR\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, pharmacological inhibitor (not specific to Mei1), non-meiotic cell type used\",\n      \"pmids\": [\"26165450\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MEI1 is a vertebrate-specific meiotic protein required for the formation of programmed DNA double-strand breaks (DSBs) at the initiation of meiotic recombination; it acts upstream of DSB-repair factors (RAD51, DMC1) and physically interacts with the pre-DSB complex proteins ANKRD31, IHO1, REC114, and MEI4, with loss-of-function causing meiotic arrest at zygotene, failure of RAD51 loading onto chromosomes, and sterility in both sexes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MEI1 is a meiotic protein required for the formation of programmed DNA double-strand breaks (DSBs) that initiate meiotic recombination [#1]. Mouse loss-of-function mutants arrest at zygotene with failure of RAD51 to load onto meiotic chromosomes [#0], and reduced γH2AX at leptonema comparable to Spo11-null mice identifies a defect in DSB induction rather than in the downstream repair machinery, since cisplatin-induced breaks restore RAD51 loading in mutant spermatocytes [#1]. Genetic epistasis places MEI1 upstream of DMC1, confirming it acts before homologous recombination-mediated DSB repair [#2]. Mechanistically, human MEI1 physically interacts with the DSB-promoting complex proteins ANKRD31, IHO1, REC114, and MEI4, and pathogenic biallelic variants disrupt these interactions [#3]. In humans, biallelic MEI1 variants cause infertility through reduced protein levels, aberrant splicing, and protein truncation [#4, #5], with patient embryos showing high rates of aneuploidy [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established that MEI1 is required for homologous chromosome synapsis and acts upstream of RAD51 loading, framing it as an early meiotic factor rather than a repair protein.\",\n      \"evidence\": \"Forward genetic mouse screen with RAD51 immunofluorescence on meiotic chromosomes\",\n      \"pmids\": [\"11820814\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the molecular step MEI1 controls\", \"No biochemical activity or partner identified\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Pinpointed the defect to programmed DSB formation itself, distinguishing MEI1 from the recombinational repair machinery.\",\n      \"evidence\": \"Positional cloning, γH2AX quantification, cisplatin rescue, and comparison with Spo11-null spermatocytes\",\n      \"pmids\": [\"14668445\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not show how MEI1 promotes DSB formation mechanistically\", \"Relationship to the Spo11 cleavage machinery left undefined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Ordered MEI1 upstream of DMC1 in the recombination pathway via epistasis, confirming it acts before DSB repair in both sexes.\",\n      \"evidence\": \"Mei1−/−; Dmc1−/− double-mutant phenotypic analysis of spermatogenesis and oogenesis\",\n      \"pmids\": [\"15928951\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Genetic order does not reveal direct molecular partners\", \"No physical interaction tested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Connected human MEI1 mutations to infertility by defining their molecular consequences on protein level and splicing.\",\n      \"evidence\": \"Western blotting and minigene splicing assays of patient variants in vitro\",\n      \"pmids\": [\"34037756\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vitro consequences not linked to meiotic phenotype in patient germ cells\", \"No functional rescue\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Provided the first physical-interaction basis for MEI1 function by linking it to the pre-DSB complex and showing patient variants disrupt these contacts.\",\n      \"evidence\": \"Co-immunoprecipitation of wild-type and mutant MEI1 with ANKRD31, IHO1, REC114, MEI4\",\n      \"pmids\": [\"36759719\", \"41706353\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab, no reciprocal pulldown or structural validation\", \"Stoichiometry and direct versus indirect binding undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended the phenotypic consequence to human embryos, linking a truncating MEI1 deletion to aneuploidy.\",\n      \"evidence\": \"Whole-exome/cDNA sequencing, western blot, immunofluorescence, and preimplantation genetic testing\",\n      \"pmids\": [\"40164922\", \"41315153\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Causal mechanism from truncated protein to aneuploidy not established\", \"Localization data from overexpression in non-meiotic cell line\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The biochemical activity by which MEI1 promotes DSB formation and its precise role within the pre-DSB complex remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of MEI1 or its complex\", \"No defined enzymatic or scaffolding activity\", \"Direct versus indirect role in Spo11-mediated cleavage unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 1, 2, 5]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"ANKRD31\", \"IHO1\", \"REC114\", \"MEI4\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}