{"gene":"CCDC39","run_date":"2026-06-09T22:57:17","timeline":{"discoveries":[{"year":2010,"finding":"CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms (IDAs) and the dynein regulatory complex (DRC). Loss-of-function mutations abolish this assembly, resulting in abnormal ciliary beating.","method":"Positional cloning in dogs, identification of human loss-of-function mutations, immunofluorescence localization to ciliary axonemes, functional analysis of ciliary motility","journal":"Nature genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct localization experiment (IF on axonemes) combined with loss-of-function phenotypic analysis in both human and dog models, replicated across labs in subsequent studies","pmids":["21131972"],"is_preprint":false},{"year":2013,"finding":"CCDC39 and CCDC40 are the two primary genes responsible for PCD with axonemal disorganization and IDA loss; all pathogenic mutations identified were null alleles (nonsense, splice, frameshift), indicating complete protein loss underlies the defect. Radial spoke structures are largely intact in these patients, clarifying that the ultrastructural defect is specifically IDA and microtubular disorganization.","method":"Sequencing of CCDC39 and CCDC40 in 54 families; transmission electron microscopy of ciliary ultrastructure","journal":"Human mutation","confidence":"High","confidence_rationale":"Tier 2 / Strong — large cohort sequencing with ultrastructural TEM confirmation, independently replicated across multiple labs","pmids":["23255504"],"is_preprint":false},{"year":2012,"finding":"CCDC39 mutations cause PCD with IDA defects and axonemal disorganization; the same ultrastructural defects are present in sperm flagella of affected males, demonstrating CCDC39 is required for flagellar as well as ciliary axonemal integrity.","method":"Sequencing of CCDC39 in patient cohort; quantitative ultrastructural analysis of cilia and sperm flagella by TEM","journal":"Journal of medical genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — orthogonal methods (sequencing + TEM ultrastructure) in large cohort, replicated findings","pmids":["22693285"],"is_preprint":false},{"year":2018,"finding":"Ccdc39 protein localizes to the axoneme of motile cilia in ependymal cells and choroid plexus; loss of Ccdc39 causes shorter ependymal cilia with disorganized microtubules and absent inner arm dynein, abolishing orchestrated ciliary beating and unidirectional CSF flow, leading to hydrocephalus.","method":"Whole-genome sequencing of prh mouse mutant; immunofluorescence localization; high-speed video microscopy of ciliary beating and CSF flow; TEM of cilia ultrastructure","journal":"Development (Cambridge, England)","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (localization, ultrastructure, functional motility assay) in genetic mouse model","pmids":["29317443"],"is_preprint":false},{"year":2024,"finding":"CCDC39 and CCDC40 form a molecular ruler complex that maintains 96 nm repeat units along ciliary axonemes. Disease-causing variants in CCDC39 cause axonemal absence of IDA heavy chains DNAH1, DNAH6, and DNAH7 (including centrin2-containing IDAs), as well as abnormal assembly of GAS8 and DNALI1, demonstrating that the CCDC39/CCDC40 ruler is required for assembly of specific IDA subtypes.","method":"Next-generation sequencing for variant identification; immunofluorescence analysis of respiratory ciliary axonemes in cohort of 51 individuals","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — immunofluorescence in large patient cohort identifies specific downstream IDA components, single lab, single primary method (IF)","pmids":["39056782"],"is_preprint":false},{"year":2023,"finding":"Pathogenic variants in CCDC39 cause absence or severe reduction of CCDC39 protein in sperm flagella, and this is accompanied by loss of CCDC40 in flagella of CCDC39-mutant individuals, revealing an interaction between CCDC39 and CCDC40 in sperm flagella (CCDC40 depends on CCDC39 for flagellar localization).","method":"Immunofluorescence microscopy on sperm flagella from patients with CCDC39 mutations; next-generation sequencing","journal":"Frontiers in genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct IF evidence of co-dependency of CCDC39 and CCDC40 in flagella, single lab","pmids":["36873931"],"is_preprint":false},{"year":2021,"finding":"A missense loss-of-function mutation in CCDC39 (p.Leu328Pro) results in near-complete absence of CCDC39 protein in spermatozoa (confirmed by immunofluorescence and western blot) and causes multiple morphological abnormalities of sperm flagella (MMAF) alongside PCD, establishing CCDC39 as required for normal sperm flagella morphology.","method":"Whole-exome sequencing; transmission electron microscopy of sperm flagella; immunofluorescence staining; western blotting","journal":"Reproductive biomedicine online","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — orthogonal methods (WES, TEM, IF, WB) in single case/family, single lab","pmids":["34674941"],"is_preprint":false},{"year":2019,"finding":"Loss of Ccdc39 in rats (via CRISPR/Cas9) causes progressive hydrocephalus with impaired glymphatic CSF flow along cerebral arteries; double mutants with L1cam gene mutation show accelerated early hydrocephalus, placing Ccdc39 in a genetic interaction with L1cam in CSF flow regulation.","method":"CRISPR/Cas9 knockin rat model; MRI imaging; glymphatic flow assessment; genetic epistasis with L1cam mutation","journal":"Disease models & mechanisms","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis in CRISPR model with imaging readout, single lab","pmids":["31771992"],"is_preprint":false},{"year":2025,"finding":"Conditional knockout of Ccdc39 specifically in adult ependymal cells causes transient ventricular enlargement and increased periventricular microglial density, demonstrating that CCDC39 function in ependymal motile cilia is specifically required for ventricular homeostasis in the adult brain.","method":"Conditional knockout mouse model targeting ependymal cells; MRI volumetry; immunohistochemistry","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 2 / Weak — preprint, single lab, limited methodological detail in abstract","pmids":[],"is_preprint":true}],"current_model":"CCDC39 (also known as CFAP59/FAP59) forms a molecular ruler complex with CCDC40 that maintains the 96 nm axonemal repeat unit in motile cilia and sperm flagella; it localizes to the ciliary axoneme and is essential for assembly of inner dynein arms (specifically IDA heavy chains DNAH1, DNAH6, DNAH7, and centrin2-containing IDAs) and the dynein regulatory complex, such that loss-of-function results in IDA absence, axonemal disorganization, abnormal ciliary beating, defective mucociliary clearance, impaired CSF flow (hydrocephalus), and male infertility due to multiple morphological abnormalities of sperm flagella."},"narrative":{"mechanistic_narrative":"CCDC39 is an axonemal protein essential for the assembly and motility of motile cilia and sperm flagella [PMID:21131972]. It forms a molecular ruler complex with CCDC40 that establishes and maintains the 96 nm repeat unit along the ciliary axoneme; CCDC40 depends on CCDC39 for its flagellar localization [PMID:39056782, PMID:36873931]. This ruler is specifically required for assembly of inner dynein arms and the dynein regulatory complex, and its loss leads to axonemal absence of IDA heavy chains DNAH1, DNAH6, and DNAH7 (including centrin2-containing IDAs) and abnormal assembly of GAS8 and DNALI1, while radial spoke structures remain largely intact [PMID:23255504, PMID:39056782]. Loss of CCDC39 produces inner dynein arm absence and microtubular disorganization, abolishing coordinated ciliary beating [PMID:21131972, PMID:23255504]. The resulting phenotypes span multiple ciliated tissues: respiratory primary ciliary dyskinesia from defective mucociliary clearance, hydrocephalus from impaired ependymal cilia-driven CSF flow, and male infertility with multiple morphological abnormalities of sperm flagella [PMID:22693285, PMID:29317443, PMID:34674941]. Pathogenic CCDC39 alleles establish it, together with CCDC40, as a primary genetic cause of PCD with axonemal disorganization and IDA loss [PMID:23255504].","teleology":[{"year":2010,"claim":"Established CCDC39 as an axonemal protein whose loss disrupts inner dynein arm and dynein regulatory complex assembly, answering what cellular structure depends on it.","evidence":"Positional cloning in dogs, human loss-of-function mutation identification, immunofluorescence to ciliary axonemes, and ciliary motility analysis","pmids":["21131972"],"confidence":"High","gaps":["Did not define a direct molecular partner of CCDC39","Mechanism by which it specifies IDA/DRC assembly not yet established","Did not address sperm flagella"]},{"year":2012,"claim":"Extended the requirement for CCDC39 from respiratory cilia to sperm flagella, showing the same axonemal defect underlies male infertility.","evidence":"CCDC39 sequencing in patient cohort with quantitative TEM of cilia and sperm flagella","pmids":["22693285"],"confidence":"High","gaps":["Did not identify which specific IDA subtypes are lost","No molecular interaction partners defined"]},{"year":2013,"claim":"Defined CCDC39 (with CCDC40) as a primary cause of PCD via null alleles and localized the ultrastructural defect specifically to IDAs and microtubular disorganization, sparing radial spokes.","evidence":"Sequencing of CCDC39 and CCDC40 in 54 families with TEM ultrastructure","pmids":["23255504"],"confidence":"High","gaps":["Did not establish the physical CCDC39–CCDC40 interaction directly","Molecular ruler function not yet demonstrated"]},{"year":2018,"claim":"Demonstrated in a mammalian genetic model that CCDC39 in ependymal and choroid plexus motile cilia drives unidirectional CSF flow, linking its axonemal role to hydrocephalus.","evidence":"Whole-genome sequencing of prh mouse mutant, immunofluorescence, high-speed video microscopy, and TEM","pmids":["29317443"],"confidence":"High","gaps":["Did not resolve cell-autonomous vs systemic contributions to hydrocephalus","Adult versus developmental requirement not separated"]},{"year":2019,"claim":"Placed Ccdc39 in a genetic interaction with L1cam in CSF flow regulation, showing combinatorial control of hydrocephalus severity.","evidence":"CRISPR/Cas9 knockin rat model with MRI, glymphatic flow assessment, and epistasis with L1cam","pmids":["31771992"],"confidence":"Medium","gaps":["Molecular basis of the Ccdc39–L1cam interaction unknown","Single lab"]},{"year":2021,"claim":"Showed a missense allele behaves as loss-of-function by destabilizing CCDC39 protein and causing MMAF, connecting protein abundance to flagellar morphology.","evidence":"Whole-exome sequencing, TEM, immunofluorescence, and western blot in a single family","pmids":["34674941"],"confidence":"Medium","gaps":["Single case/family, single lab","Did not define why p.Leu328Pro destabilizes the protein"]},{"year":2023,"claim":"Provided direct evidence of CCDC39–CCDC40 co-dependency in flagella, showing CCDC40 requires CCDC39 for its flagellar localization.","evidence":"Immunofluorescence of sperm flagella from CCDC39-mutant patients with NGS","pmids":["36873931"],"confidence":"Medium","gaps":["Did not demonstrate a direct biochemical interaction","Reciprocal dependency (CCDC39 on CCDC40) not tested here","Single lab"]},{"year":2024,"claim":"Defined the CCDC39/CCDC40 complex as a 96 nm molecular ruler and identified the specific IDA components (DNAH1/6/7, centrin2-IDAs, GAS8, DNALI1) whose assembly depends on it.","evidence":"Immunofluorescence of respiratory ciliary axonemes in 51 individuals with NGS variant identification","pmids":["39056782"],"confidence":"Medium","gaps":["Single primary method (IF), single lab","Direct biochemical reconstitution of ruler periodicity not shown","Mechanism of how the ruler templates 96 nm spacing not resolved"]},{"year":2025,"claim":"Isolated the adult-specific requirement for CCDC39 in ependymal cilia, showing its loss causes transient ventricular enlargement and microglial response distinct from developmental defects.","evidence":"Conditional ependymal knockout mouse with MRI volumetry and immunohistochemistry (preprint)","pmids":[],"confidence":"Low","gaps":["Preprint, single lab, limited methodological detail","Mechanism linking ciliary loss to microglial density not established","Transient nature of phenotype not mechanistically explained"]},{"year":null,"claim":"How the CCDC39/CCDC40 ruler physically templates the 96 nm axonemal repeat and selectively recruits specific IDA subtypes remains to be defined at the structural and biochemical level.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of the CCDC39/CCDC40 ruler in the timeline","Direct binding of CCDC39 to individual IDA components not demonstrated","Mechanism of periodicity measurement unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,4]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[4,5]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,1]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,4]}],"complexes":["CCDC39/CCDC40 molecular ruler complex"],"partners":["CCDC40"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9UFE4","full_name":"Coiled-coil domain-containing protein 39","aliases":[],"length_aa":941,"mass_kda":109.9,"function":"Required for assembly of dynein regulatory complex (DRC) and inner dynein arm (IDA) complexes, which are responsible for ciliary beat regulation, thereby playing a central role in motility in cilia and flagella (PubMed:21131972). Probably acts together with CCDC40 to form a molecular ruler that determines the 96 nanometer (nm) repeat length and arrangements of components in cilia and flagella (By similarity). Not required for outer dynein arm complexes assembly (PubMed:21131972)","subcellular_location":"Cytoplasm, cytoskeleton, cilium axoneme","url":"https://www.uniprot.org/uniprotkb/Q9UFE4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CCDC39","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"DYNC1LI1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/CCDC39","total_profiled":1310},"omim":[{"mim_id":"619827","title":"INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL RECESSIVE 75, WITH NEUROPSYCHIATRIC FEATURES AND VARIANT LISSENCEPHALY; MRT75","url":"https://www.omim.org/entry/619827"},{"mim_id":"618695","title":"CILIARY DYSKINESIA, PRIMARY, 42; CILD42","url":"https://www.omim.org/entry/618695"},{"mim_id":"614086","title":"MULTICILIATE DIFFERENTIATION AND DNA SYNTHESIS-ASSOCIATED CELL CYCLE PROTEIN; MCIDAS","url":"https://www.omim.org/entry/614086"},{"mim_id":"613808","title":"CILIARY DYSKINESIA, PRIMARY, 15; CILD15","url":"https://www.omim.org/entry/613808"},{"mim_id":"613807","title":"CILIARY DYSKINESIA, PRIMARY, 14; CILD14","url":"https://www.omim.org/entry/613807"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Nucleoplasm","reliability":"Uncertain"},{"location":"Centrosome","reliability":"Uncertain"},{"location":"Basal body","reliability":"Uncertain"},{"location":"Acrosome","reliability":"Uncertain"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":20.2},{"tissue":"retina","ntpm":20.2},{"tissue":"skin 1","ntpm":19.1}],"url":"https://www.proteinatlas.org/search/CCDC39"},"hgnc":{"alias_symbol":["DKFZp434A128","CILD14","FAP59","CFAP59"],"prev_symbol":[]},"alphafold":{"accession":"Q9UFE4","domains":[{"cath_id":"1.20.5","chopping":"664-711","consensus_level":"medium","plddt":77.7677,"start":664,"end":711},{"cath_id":"1.20.5","chopping":"716-816","consensus_level":"medium","plddt":82.1637,"start":716,"end":816}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UFE4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UFE4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UFE4-F1-predicted_aligned_error_v6.png","plddt_mean":78.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CCDC39","jax_strain_url":"https://www.jax.org/strain/search?query=CCDC39"},"sequence":{"accession":"Q9UFE4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9UFE4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9UFE4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UFE4"}},"corpus_meta":[{"pmid":"21131972","id":"PMC_21131972","title":"CCDC39 is required for assembly of inner dynein arms and the dynein regulatory complex and for normal ciliary motility in humans and dogs.","date":"2010","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/21131972","citation_count":273,"is_preprint":false},{"pmid":"23255504","id":"PMC_23255504","title":"Mutations in CCDC39 and CCDC40 are the major cause of primary ciliary dyskinesia with axonemal disorganization and absent inner dynein arms.","date":"2013","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/23255504","citation_count":158,"is_preprint":false},{"pmid":"22693285","id":"PMC_22693285","title":"Delineation of CCDC39/CCDC40 mutation spectrum and associated phenotypes in primary ciliary dyskinesia.","date":"2012","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/22693285","citation_count":79,"is_preprint":false},{"pmid":"29317443","id":"PMC_29317443","title":"A mutation in Ccdc39 causes neonatal hydrocephalus with abnormal motile cilia development in mice.","date":"2018","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/29317443","citation_count":64,"is_preprint":false},{"pmid":"34674941","id":"PMC_34674941","title":"A novel CCDC39 mutation causes multiple morphological abnormalities of the flagella in a primary ciliary dyskinesia patient.","date":"2021","source":"Reproductive biomedicine online","url":"https://pubmed.ncbi.nlm.nih.gov/34674941","citation_count":29,"is_preprint":false},{"pmid":"31771992","id":"PMC_31771992","title":"Impaired neural differentiation and glymphatic CSF flow in the Ccdc39 rat model of neonatal hydrocephalus: genetic interaction with L1cam.","date":"2019","source":"Disease models & mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/31771992","citation_count":28,"is_preprint":false},{"pmid":"32032950","id":"PMC_32032950","title":"Neonatal hydrocephalus leads to white matter neuroinflammation and injury in the corpus callosum of Ccdc39 hydrocephalic mice.","date":"2020","source":"Journal of neurosurgery. Pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/32032950","citation_count":27,"is_preprint":false},{"pmid":"36873931","id":"PMC_36873931","title":"Pathogenic gene variants in CCDC39, CCDC40, RSPH1, RSPH9, HYDIN, and SPEF2 cause defects of sperm flagella composition and male infertility.","date":"2023","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36873931","citation_count":25,"is_preprint":false},{"pmid":"33005176","id":"PMC_33005176","title":"Ultrastructural Sperm Flagellum Defects in a Patient With CCDC39 Compound Heterozygous Mutations and Primary Ciliary Dyskinesia/Situs Viscerum Inversus.","date":"2020","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33005176","citation_count":12,"is_preprint":false},{"pmid":"39056782","id":"PMC_39056782","title":"Primary Ciliary Dyskinesia Associated Disease-Causing Variants in CCDC39 and CCDC40 Cause Axonemal Absence of Inner Dynein Arm Heavy Chains DNAH1, DNAH6, and DNAH7.","date":"2024","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/39056782","citation_count":9,"is_preprint":false},{"pmid":"35233959","id":"PMC_35233959","title":"Copy number variation of the CCDC39 gene is associated with growth traits in Chinese cattle.","date":"2022","source":"Veterinary medicine and science","url":"https://pubmed.ncbi.nlm.nih.gov/35233959","citation_count":7,"is_preprint":false},{"pmid":"35795318","id":"PMC_35795318","title":"Biallelic Variants in CCDC39 Gene Lead to Primary Ciliary Dyskinesia and Kartagener Syndrome.","date":"2022","source":"BioMed research international","url":"https://pubmed.ncbi.nlm.nih.gov/35795318","citation_count":5,"is_preprint":false},{"pmid":"37296418","id":"PMC_37296418","title":"Early postnatal microglial ablation in the Ccdc39 mouse model reveals adverse effects on brain development and in neonatal hydrocephalus.","date":"2023","source":"Fluids and barriers of the CNS","url":"https://pubmed.ncbi.nlm.nih.gov/37296418","citation_count":4,"is_preprint":false},{"pmid":"39867101","id":"PMC_39867101","title":"Chronic Cough, Dyspnea, and a Novel CCDC39 Variant: A Case Report of Heterotaxy Syndrome Without Cardiac Anomalies and Associated Primary Ciliary Dyskinesia.","date":"2024","source":"Cureus","url":"https://pubmed.ncbi.nlm.nih.gov/39867101","citation_count":1,"is_preprint":false},{"pmid":"40763972","id":"PMC_40763972","title":"[Clinical and genetic analysis of a child with Primary ciliary dyskinesia variants and co-existence of CCDC39 gene variants and 22q11.21 deletion].","date":"2025","source":"Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/40763972","citation_count":0,"is_preprint":false},{"pmid":"41082487","id":"PMC_41082487","title":"CCDC39 Mutation-Related Primary Ciliary Dyskinesia with Congenitally Corrected Transposition of the Great Arteries: A Case Report.","date":"2025","source":"The American journal of case reports","url":"https://pubmed.ncbi.nlm.nih.gov/41082487","citation_count":0,"is_preprint":false},{"pmid":"42210652","id":"PMC_42210652","title":"A homozygous splicing mutation in CCDC39 caused multiple morphological abnormalities of the flagella in an infertile man with primary ciliary dyskinesia.","date":"2026","source":"Asian journal of andrology","url":"https://pubmed.ncbi.nlm.nih.gov/42210652","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.07.06.663378","title":"Cerebrospinal fluid-driven ependymal motile cilia defects are implicated in multiple sclerosis pathophysiology","date":"2025-07-06","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.06.663378","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.22.639695","title":"AggreBots: configuring CiliaBots through guided, modular tissue aggregation","date":"2025-02-27","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.22.639695","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13255,"output_tokens":2209,"usd":0.03645,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9288,"output_tokens":3003,"usd":0.060757,"stage2_stop_reason":"end_turn"},"total_usd":0.097207,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2010,\n      \"finding\": \"CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms (IDAs) and the dynein regulatory complex (DRC). Loss-of-function mutations abolish this assembly, resulting in abnormal ciliary beating.\",\n      \"method\": \"Positional cloning in dogs, identification of human loss-of-function mutations, immunofluorescence localization to ciliary axonemes, functional analysis of ciliary motility\",\n      \"journal\": \"Nature genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct localization experiment (IF on axonemes) combined with loss-of-function phenotypic analysis in both human and dog models, replicated across labs in subsequent studies\",\n      \"pmids\": [\"21131972\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CCDC39 and CCDC40 are the two primary genes responsible for PCD with axonemal disorganization and IDA loss; all pathogenic mutations identified were null alleles (nonsense, splice, frameshift), indicating complete protein loss underlies the defect. Radial spoke structures are largely intact in these patients, clarifying that the ultrastructural defect is specifically IDA and microtubular disorganization.\",\n      \"method\": \"Sequencing of CCDC39 and CCDC40 in 54 families; transmission electron microscopy of ciliary ultrastructure\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — large cohort sequencing with ultrastructural TEM confirmation, independently replicated across multiple labs\",\n      \"pmids\": [\"23255504\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CCDC39 mutations cause PCD with IDA defects and axonemal disorganization; the same ultrastructural defects are present in sperm flagella of affected males, demonstrating CCDC39 is required for flagellar as well as ciliary axonemal integrity.\",\n      \"method\": \"Sequencing of CCDC39 in patient cohort; quantitative ultrastructural analysis of cilia and sperm flagella by TEM\",\n      \"journal\": \"Journal of medical genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — orthogonal methods (sequencing + TEM ultrastructure) in large cohort, replicated findings\",\n      \"pmids\": [\"22693285\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Ccdc39 protein localizes to the axoneme of motile cilia in ependymal cells and choroid plexus; loss of Ccdc39 causes shorter ependymal cilia with disorganized microtubules and absent inner arm dynein, abolishing orchestrated ciliary beating and unidirectional CSF flow, leading to hydrocephalus.\",\n      \"method\": \"Whole-genome sequencing of prh mouse mutant; immunofluorescence localization; high-speed video microscopy of ciliary beating and CSF flow; TEM of cilia ultrastructure\",\n      \"journal\": \"Development (Cambridge, England)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (localization, ultrastructure, functional motility assay) in genetic mouse model\",\n      \"pmids\": [\"29317443\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CCDC39 and CCDC40 form a molecular ruler complex that maintains 96 nm repeat units along ciliary axonemes. Disease-causing variants in CCDC39 cause axonemal absence of IDA heavy chains DNAH1, DNAH6, and DNAH7 (including centrin2-containing IDAs), as well as abnormal assembly of GAS8 and DNALI1, demonstrating that the CCDC39/CCDC40 ruler is required for assembly of specific IDA subtypes.\",\n      \"method\": \"Next-generation sequencing for variant identification; immunofluorescence analysis of respiratory ciliary axonemes in cohort of 51 individuals\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — immunofluorescence in large patient cohort identifies specific downstream IDA components, single lab, single primary method (IF)\",\n      \"pmids\": [\"39056782\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Pathogenic variants in CCDC39 cause absence or severe reduction of CCDC39 protein in sperm flagella, and this is accompanied by loss of CCDC40 in flagella of CCDC39-mutant individuals, revealing an interaction between CCDC39 and CCDC40 in sperm flagella (CCDC40 depends on CCDC39 for flagellar localization).\",\n      \"method\": \"Immunofluorescence microscopy on sperm flagella from patients with CCDC39 mutations; next-generation sequencing\",\n      \"journal\": \"Frontiers in genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct IF evidence of co-dependency of CCDC39 and CCDC40 in flagella, single lab\",\n      \"pmids\": [\"36873931\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"A missense loss-of-function mutation in CCDC39 (p.Leu328Pro) results in near-complete absence of CCDC39 protein in spermatozoa (confirmed by immunofluorescence and western blot) and causes multiple morphological abnormalities of sperm flagella (MMAF) alongside PCD, establishing CCDC39 as required for normal sperm flagella morphology.\",\n      \"method\": \"Whole-exome sequencing; transmission electron microscopy of sperm flagella; immunofluorescence staining; western blotting\",\n      \"journal\": \"Reproductive biomedicine online\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — orthogonal methods (WES, TEM, IF, WB) in single case/family, single lab\",\n      \"pmids\": [\"34674941\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Loss of Ccdc39 in rats (via CRISPR/Cas9) causes progressive hydrocephalus with impaired glymphatic CSF flow along cerebral arteries; double mutants with L1cam gene mutation show accelerated early hydrocephalus, placing Ccdc39 in a genetic interaction with L1cam in CSF flow regulation.\",\n      \"method\": \"CRISPR/Cas9 knockin rat model; MRI imaging; glymphatic flow assessment; genetic epistasis with L1cam mutation\",\n      \"journal\": \"Disease models & mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis in CRISPR model with imaging readout, single lab\",\n      \"pmids\": [\"31771992\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Conditional knockout of Ccdc39 specifically in adult ependymal cells causes transient ventricular enlargement and increased periventricular microglial density, demonstrating that CCDC39 function in ependymal motile cilia is specifically required for ventricular homeostasis in the adult brain.\",\n      \"method\": \"Conditional knockout mouse model targeting ependymal cells; MRI volumetry; immunohistochemistry\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 2 / Weak — preprint, single lab, limited methodological detail in abstract\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"CCDC39 (also known as CFAP59/FAP59) forms a molecular ruler complex with CCDC40 that maintains the 96 nm axonemal repeat unit in motile cilia and sperm flagella; it localizes to the ciliary axoneme and is essential for assembly of inner dynein arms (specifically IDA heavy chains DNAH1, DNAH6, DNAH7, and centrin2-containing IDAs) and the dynein regulatory complex, such that loss-of-function results in IDA absence, axonemal disorganization, abnormal ciliary beating, defective mucociliary clearance, impaired CSF flow (hydrocephalus), and male infertility due to multiple morphological abnormalities of sperm flagella.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CCDC39 is an axonemal protein essential for the assembly and motility of motile cilia and sperm flagella [#0]. It forms a molecular ruler complex with CCDC40 that establishes and maintains the 96 nm repeat unit along the ciliary axoneme; CCDC40 depends on CCDC39 for its flagellar localization [#4, #5]. This ruler is specifically required for assembly of inner dynein arms and the dynein regulatory complex, and its loss leads to axonemal absence of IDA heavy chains DNAH1, DNAH6, and DNAH7 (including centrin2-containing IDAs) and abnormal assembly of GAS8 and DNALI1, while radial spoke structures remain largely intact [#1, #4]. Loss of CCDC39 produces inner dynein arm absence and microtubular disorganization, abolishing coordinated ciliary beating [#0, #1]. The resulting phenotypes span multiple ciliated tissues: respiratory primary ciliary dyskinesia from defective mucociliary clearance, hydrocephalus from impaired ependymal cilia-driven CSF flow, and male infertility with multiple morphological abnormalities of sperm flagella [#2, #3, #6]. Pathogenic CCDC39 alleles establish it, together with CCDC40, as a primary genetic cause of PCD with axonemal disorganization and IDA loss [#1].\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Established CCDC39 as an axonemal protein whose loss disrupts inner dynein arm and dynein regulatory complex assembly, answering what cellular structure depends on it.\",\n      \"evidence\": \"Positional cloning in dogs, human loss-of-function mutation identification, immunofluorescence to ciliary axonemes, and ciliary motility analysis\",\n      \"pmids\": [\"21131972\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Did not define a direct molecular partner of CCDC39\",\n        \"Mechanism by which it specifies IDA/DRC assembly not yet established\",\n        \"Did not address sperm flagella\"\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended the requirement for CCDC39 from respiratory cilia to sperm flagella, showing the same axonemal defect underlies male infertility.\",\n      \"evidence\": \"CCDC39 sequencing in patient cohort with quantitative TEM of cilia and sperm flagella\",\n      \"pmids\": [\"22693285\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Did not identify which specific IDA subtypes are lost\",\n        \"No molecular interaction partners defined\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined CCDC39 (with CCDC40) as a primary cause of PCD via null alleles and localized the ultrastructural defect specifically to IDAs and microtubular disorganization, sparing radial spokes.\",\n      \"evidence\": \"Sequencing of CCDC39 and CCDC40 in 54 families with TEM ultrastructure\",\n      \"pmids\": [\"23255504\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Did not establish the physical CCDC39–CCDC40 interaction directly\",\n        \"Molecular ruler function not yet demonstrated\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrated in a mammalian genetic model that CCDC39 in ependymal and choroid plexus motile cilia drives unidirectional CSF flow, linking its axonemal role to hydrocephalus.\",\n      \"evidence\": \"Whole-genome sequencing of prh mouse mutant, immunofluorescence, high-speed video microscopy, and TEM\",\n      \"pmids\": [\"29317443\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Did not resolve cell-autonomous vs systemic contributions to hydrocephalus\",\n        \"Adult versus developmental requirement not separated\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Placed Ccdc39 in a genetic interaction with L1cam in CSF flow regulation, showing combinatorial control of hydrocephalus severity.\",\n      \"evidence\": \"CRISPR/Cas9 knockin rat model with MRI, glymphatic flow assessment, and epistasis with L1cam\",\n      \"pmids\": [\"31771992\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular basis of the Ccdc39–L1cam interaction unknown\",\n        \"Single lab\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showed a missense allele behaves as loss-of-function by destabilizing CCDC39 protein and causing MMAF, connecting protein abundance to flagellar morphology.\",\n      \"evidence\": \"Whole-exome sequencing, TEM, immunofluorescence, and western blot in a single family\",\n      \"pmids\": [\"34674941\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single case/family, single lab\",\n        \"Did not define why p.Leu328Pro destabilizes the protein\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Provided direct evidence of CCDC39–CCDC40 co-dependency in flagella, showing CCDC40 requires CCDC39 for its flagellar localization.\",\n      \"evidence\": \"Immunofluorescence of sperm flagella from CCDC39-mutant patients with NGS\",\n      \"pmids\": [\"36873931\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Did not demonstrate a direct biochemical interaction\",\n        \"Reciprocal dependency (CCDC39 on CCDC40) not tested here\",\n        \"Single lab\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined the CCDC39/CCDC40 complex as a 96 nm molecular ruler and identified the specific IDA components (DNAH1/6/7, centrin2-IDAs, GAS8, DNALI1) whose assembly depends on it.\",\n      \"evidence\": \"Immunofluorescence of respiratory ciliary axonemes in 51 individuals with NGS variant identification\",\n      \"pmids\": [\"39056782\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single primary method (IF), single lab\",\n        \"Direct biochemical reconstitution of ruler periodicity not shown\",\n        \"Mechanism of how the ruler templates 96 nm spacing not resolved\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Isolated the adult-specific requirement for CCDC39 in ependymal cilia, showing its loss causes transient ventricular enlargement and microglial response distinct from developmental defects.\",\n      \"evidence\": \"Conditional ependymal knockout mouse with MRI volumetry and immunohistochemistry (preprint)\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Preprint, single lab, limited methodological detail\",\n        \"Mechanism linking ciliary loss to microglial density not established\",\n        \"Transient nature of phenotype not mechanistically explained\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the CCDC39/CCDC40 ruler physically templates the 96 nm axonemal repeat and selectively recruits specific IDA subtypes remains to be defined at the structural and biochemical level.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of the CCDC39/CCDC40 ruler in the timeline\",\n        \"Direct binding of CCDC39 to individual IDA components not demonstrated\",\n        \"Mechanism of periodicity measurement unresolved\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [4, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005930\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"complexes\": [\n      \"CCDC39/CCDC40 molecular ruler complex\"\n    ],\n    \"partners\": [\n      \"CCDC40\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}