{"gene":"DNAH9","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2005,"finding":"DNAH5 and DNAH9 show distinct regional distribution along the ciliary axoneme in normal human respiratory epithelial cells, indicating the existence of at least two distinct outer dynein arm (ODA) types. DNAH5 localizes along the full axoneme while DNAH9 has a different regional distribution, suggesting they form part of different ODA subtypes.","method":"High-resolution immunofluorescence imaging with specific antibodies in human respiratory epithelial and sperm cells","journal":"American journal of respiratory and critical care medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct subcellular localization by immunofluorescence with functional consequence (ODA typing), single lab but applied to multiple patient and control samples","pmids":["15750039"],"is_preprint":false},{"year":2001,"finding":"DNAH9 encodes a 4486 amino acid axonemal beta heavy chain dynein consisting of an N-terminal stem and a globular C-terminus containing four P-loops that constitute the motor domain, with ATPase activity coupled to conformational changes driving cilia and flagella bending.","method":"cDNA cloning, RT-PCR, 5' RACE, cDNA library screening, genomic sequencing; protein domain analysis showing homology to sea urchin axonemal beta heavy chain dyneins (67% identity)","journal":"Genomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — full cDNA/protein sequence determination with domain identification, single lab but comprehensive molecular characterization","pmids":["11247663"],"is_preprint":false},{"year":2018,"finding":"DNAH9 and its partner heavy chain DNAH5 co-localize to type 2 ODAs of the distal cilium. Loss of DNAH9 (due to biallelic mutations) causes loss of DNAH9/DNAH5-containing type 2 ODAs restricted to the distal cilia region, conferring reduced beating frequency with a subtle beating pattern defect affecting the motility of the distal cilia portion.","method":"Immunofluorescence localization, 3D electron tomography ultrastructural studies, high-speed video microscopy, next-generation sequencing; Paramecium DNAH9 knockdown as functional confirmation","journal":"American journal of human genetics","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods (immunofluorescence, 3D electron tomography, functional motility assay, cross-species knockdown), replicated across multiple patients","pmids":["30471717"],"is_preprint":false},{"year":2022,"finding":"DNAH9 interacts with CCDC114 and GAS8 (as shown by co-immunoprecipitation), and loss of DNAH9 (knockdown in mice) diminishes the protein levels of CCDC114 and GAS8.","method":"Co-immunoprecipitation, immunostaining, western blot in Dnah9 knockdown mice","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — reciprocal binding shown by co-IP with protein level consequences, single lab with multiple methods","pmids":["35729109"],"is_preprint":false},{"year":2022,"finding":"Dnah9 knockout in zebrafish disturbs cardiac left-right patterning without affecting ciliogenesis in Kupffer's vesicle, and Dnah9 loss in a knockout mouse model leads to compromised cardiac function.","method":"dnah9 morpholino knockdown in zebrafish; Dnah9 knockout C57BL/6n mouse model with cardiac function assessment","journal":"Human genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic loss-of-function in two model organisms with specific phenotypic readouts, single lab","pmids":["35050399"],"is_preprint":false},{"year":2021,"finding":"DNAH9 protein is expressed in sperm tails, and loss-of-function variants in DNAH9 lead to significantly decreased DNAH9 mRNA and protein in sperm, causing outer dynein arm defects in sperm axoneme and severe asthenozoospermia without respiratory symptoms, establishing DNAH9 as required for flagellar motility.","method":"Whole exome sequencing, Sanger sequencing, TEM of sperm ultrastructure, qRT-PCR, immunofluorescence staining of sperm","journal":"Reproductive biology and endocrinology : RB&E","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — multiple complementary methods (TEM, immunofluorescence, expression analysis) in patient sperm, single lab","pmids":["33610189"],"is_preprint":false},{"year":2024,"finding":"Biallelic DNAH9 variants cause loss of outer dynein arms in sperm axoneme cross-sections and reduce expression of flagellar ultrastructure-related proteins DNAI1, DNAH1, and DNAH10, demonstrating that DNAH9 is required for proper assembly or stability of the outer dynein arm complex in flagella.","method":"Transmission electron microscopy of sperm axoneme, immunofluorescence showing reduced DNAI1, DNAH1, and DNAH10 expression in DNAH9 variant patients","journal":"Journal of human genetics","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — TEM ultrastructure plus immunofluorescence of multiple ODA components, single lab","pmids":["39523437"],"is_preprint":false},{"year":2025,"finding":"A novel DNAH9 splice-site mutation (c.3743+1G>T) leads to abnormal splicing, as demonstrated by minigene analysis, establishing that correct splicing of DNAH9 pre-mRNA is required for functional protein production.","method":"Minigene splicing assay, in silico splice prediction, Sanger sequencing","journal":"Molecular medicine reports","confidence":"Low","confidence_rationale":"Tier 3 / Weak — minigene assay in a single case report, no functional protein rescue experiment","pmids":["40376972"],"is_preprint":false}],"current_model":"DNAH9 is an axonemal beta heavy chain dynein (4486 aa) with an N-terminal stem and a C-terminal motor domain containing four P-loops for ATPase activity; it localizes specifically to type 2 outer dynein arms (ODAs) of the distal ciliary axoneme together with DNAH5, where it is required for normal cilia beating frequency and distal cilium motility, interacts with ODA-associated proteins CCDC114 and GAS8 and is required for their stability, and also functions in sperm flagella where its loss disrupts ODA assembly and reduces motility of co-dependent ODA components (DNAI1, DNAH1, DNAH10); loss of DNAH9 in vivo causes defective left-right patterning and compromised cardiac function."},"narrative":{"mechanistic_narrative":"DNAH9 is an axonemal beta heavy chain dynein that powers ciliary and flagellar beating, encoding a 4486-residue protein with an N-terminal stem and a C-terminal globular motor domain bearing four P-loops whose ATPase activity drives the conformational changes underlying axonemal bending [PMID:11247663]. Within motile cilia DNAH9 marks a distinct outer dynein arm (ODA) subtype: together with its partner heavy chain DNAH5 it occupies type 2 ODAs restricted to the distal ciliary axoneme, and biallelic loss removes these distal ODAs, lowering beat frequency and disrupting motility of the distal cilium [PMID:15750039, PMID:30471717]. DNAH9 physically associates with the ODA-related proteins CCDC114 and GAS8 and is required to maintain their protein levels, linking it to ODA docking and stability [PMID:35729109]. The same dependency operates in sperm flagella, where DNAH9 is expressed in the tail and its loss causes ODA defects with reduced levels of co-assembled components DNAI1, DNAH1 and DNAH10, producing severe asthenozoospermia [PMID:33610189, PMID:39523437]. In vivo, DNAH9 loss disturbs cardiac left-right patterning and compromises cardiac function [PMID:35050399].","teleology":[{"year":2001,"claim":"Establishing the molecular identity of DNAH9 was the prerequisite for any functional study; cloning defined it as a full-length axonemal beta heavy chain dynein with a defined motor architecture.","evidence":"cDNA cloning, RACE, and protein domain analysis revealing four P-loops and homology to sea urchin axonemal beta heavy chains","pmids":["11247663"],"confidence":"Medium","gaps":["ATPase activity inferred from domain homology, not directly measured","no structural model of the motor domain"]},{"year":2005,"claim":"It was unknown whether all ciliary ODAs were equivalent; differential axonemal distribution of DNAH9 versus DNAH5 revealed that at least two distinct ODA subtypes exist.","evidence":"High-resolution immunofluorescence of DNAH5 and DNAH9 in human respiratory epithelial and sperm cells","pmids":["15750039"],"confidence":"Medium","gaps":["molecular basis of regional targeting unresolved","functional difference between ODA subtypes not yet tested"]},{"year":2018,"claim":"The functional role of the distal ODA subtype was undefined; loss-of-function in patients pinned DNAH9/DNAH5 type 2 ODAs to distal-cilium motility and beat frequency.","evidence":"Immunofluorescence, 3D electron tomography, high-speed video microscopy in patients plus Paramecium knockdown","pmids":["30471717"],"confidence":"High","gaps":["does not resolve how the type 2 ODA is targeted distally","mechanism coupling distal ODA loss to the subtle beat defect not detailed"]},{"year":2021,"claim":"Whether DNAH9 acted in sperm as in respiratory cilia was unclear; patient analysis showed it is required for flagellar ODA integrity and motility, causing asthenozoospermia without respiratory disease.","evidence":"Whole exome sequencing, TEM of sperm ultrastructure, qRT-PCR and immunofluorescence of patient sperm","pmids":["33610189"],"confidence":"Medium","gaps":["tissue-specific phenotype (sperm vs airway) mechanism not explained","single lab"]},{"year":2022,"claim":"The basis of DNAH9's role in ODA architecture was unknown; co-IP and knockdown defined direct partners CCDC114 and GAS8 and showed DNAH9 is needed to stabilize them.","evidence":"Co-immunoprecipitation, immunostaining and western blot in Dnah9 knockdown mice","pmids":["35729109"],"confidence":"Medium","gaps":["direct versus indirect binding not distinguished","stoichiometry and assembly order within the ODA undefined"]},{"year":2022,"claim":"The organismal consequence of DNAH9 loss was untested; model-organism knockouts established a requirement in left-right patterning and cardiac function distinct from ciliogenesis itself.","evidence":"dnah9 morpholino knockdown in zebrafish and Dnah9 knockout mouse with cardiac assessment","pmids":["35050399"],"confidence":"Medium","gaps":["ciliogenesis in Kupffer's vesicle unaffected, so the motility defect driving laterality is not localized","cardiac phenotype mechanism not dissected"]},{"year":2024,"claim":"Whether DNAH9 loss propagates to other ODA subunits was open; reduced DNAI1, DNAH1 and DNAH10 in patient sperm showed DNAH9 is required for assembly/stability of the broader ODA complex in flagella.","evidence":"TEM of sperm axoneme and immunofluorescence of multiple ODA components in patients","pmids":["39523437"],"confidence":"Medium","gaps":["direct interaction with the reduced components not demonstrated","assembly hierarchy not established"]},{"year":2025,"claim":"A specific splice variant's pathogenicity was uncharacterized; minigene analysis confirmed that correct DNAH9 pre-mRNA splicing is required for functional protein.","evidence":"Minigene splicing assay and in silico prediction in a single case report","pmids":["40376972"],"confidence":"Low","gaps":["no functional protein rescue experiment","single case report"]},{"year":null,"claim":"How DNAH9-containing type 2 ODAs are specifically targeted to the distal axoneme, and the structural basis of its motor activity, remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["no structure of the DNAH9 motor domain","distal-targeting mechanism unknown","direct ATPase/motility reconstitution not reported"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003774","term_label":"cytoskeletal motor activity","supporting_discovery_ids":[1,2]},{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[1]}],"localization":[{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[0,2,5]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2,6]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[2,6]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[5,6]}],"complexes":["outer dynein arm"],"partners":["DNAH5","CCDC114","GAS8"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9NYC9","full_name":"Dynein axonemal heavy chain 9","aliases":["Axonemal beta dynein heavy chain 9","Ciliary dynein heavy chain 9"],"length_aa":4486,"mass_kda":511.9,"function":"Force generating protein required for cilia beating in respiratory epithelia (PubMed:30471717, PubMed:30471718). Produces force towards the minus ends of microtubules (PubMed:30471717, PubMed:30471718). Key component of dynein, a family of motor proteins essential for movement along microtubules (By similarity). Dynein has ATPase activity; the force-producing power stroke is thought to occur on release of ADP (PubMed:30471717, PubMed:30471718). Required for structural and functional integrity of cilia (PubMed:30471717, PubMed:30471718)","subcellular_location":"Cytoplasm, cytoskeleton, cilium axoneme; Cell projection, cilium, flagellum","url":"https://www.uniprot.org/uniprotkb/Q9NYC9/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DNAH9","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/DNAH9","total_profiled":1310},"omim":[{"mim_id":"618300","title":"CILIARY DYSKINESIA, PRIMARY, 40; CILD40","url":"https://www.omim.org/entry/618300"},{"mim_id":"618063","title":"CILIARY DYSKINESIA, PRIMARY, 38; CILD38","url":"https://www.omim.org/entry/618063"},{"mim_id":"618058","title":"CILIA- AND FLAGELLA-ASSOCIATED PROTEIN 300; CFAP300","url":"https://www.omim.org/entry/618058"},{"mim_id":"615408","title":"OUTER DYNEIN ARM DOCKING COMPLEX SUBUNIT 2; ODAD2","url":"https://www.omim.org/entry/615408"},{"mim_id":"614566","title":"DYNEIN, AXONEMAL, ASSEMBLY FACTOR 3; DNAAF3","url":"https://www.omim.org/entry/614566"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Flagellar centriole","reliability":"Supported"},{"location":"End piece","reliability":"Supported"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":13.5},{"tissue":"choroid plexus","ntpm":11.9},{"tissue":"fallopian tube","ntpm":33.1}],"url":"https://www.proteinatlas.org/search/DNAH9"},"hgnc":{"alias_symbol":["Dnahc9","KIAA0357","HL20","HL-20","DNAL1","DYH9"],"prev_symbol":["DNAH17L"]},"alphafold":{"accession":"Q9NYC9","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NYC9","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NYC9-3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NYC9-3-F1-predicted_aligned_error_v6.png","plddt_mean":92.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DNAH9","jax_strain_url":"https://www.jax.org/strain/search?query=DNAH9"},"sequence":{"accession":"Q9NYC9","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9NYC9.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9NYC9/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NYC9"}},"corpus_meta":[{"pmid":"15750039","id":"PMC_15750039","title":"Mislocalization of DNAH5 and DNAH9 in respiratory cells from patients with primary ciliary dyskinesia.","date":"2005","source":"American journal of respiratory and critical care medicine","url":"https://pubmed.ncbi.nlm.nih.gov/15750039","citation_count":231,"is_preprint":false},{"pmid":"30471717","id":"PMC_30471717","title":"Mutations in Outer Dynein Arm Heavy Chain DNAH9 Cause Motile Cilia Defects and Situs Inversus.","date":"2018","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/30471717","citation_count":101,"is_preprint":false},{"pmid":"11247663","id":"PMC_11247663","title":"Axonemal beta heavy chain dynein DNAH9: cDNA sequence, genomic structure, and investigation of its role in primary ciliary dyskinesia.","date":"2001","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/11247663","citation_count":38,"is_preprint":false},{"pmid":"33610189","id":"PMC_33610189","title":"Novel variants in DNAH9 lead to nonsyndromic severe asthenozoospermia.","date":"2021","source":"Reproductive biology and endocrinology : RB&E","url":"https://pubmed.ncbi.nlm.nih.gov/33610189","citation_count":28,"is_preprint":false},{"pmid":"35729109","id":"PMC_35729109","title":"Dnah9 mutant mice and organoid models recapitulate the clinical features of patients with PCD and provide an excellent platform for drug screening.","date":"2022","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/35729109","citation_count":19,"is_preprint":false},{"pmid":"26797031","id":"PMC_26797031","title":"Interaction between the DNAH9 gene and early smoke exposure in bronchial hyperresponsiveness.","date":"2016","source":"The European respiratory journal","url":"https://pubmed.ncbi.nlm.nih.gov/26797031","citation_count":18,"is_preprint":false},{"pmid":"35050399","id":"PMC_35050399","title":"Biallelic DNAH9 mutations are identified in Chinese patients with defective left-right patterning and cilia-related complex congenital heart disease.","date":"2022","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35050399","citation_count":14,"is_preprint":false},{"pmid":"36712782","id":"PMC_36712782","title":"A Novel DNAH9 Gene Mutation Causing Primary Ciliary Dyskinesia With an Unusual Association of Jejunal Atresia in a Bahraini Child.","date":"2022","source":"Cureus","url":"https://pubmed.ncbi.nlm.nih.gov/36712782","citation_count":4,"is_preprint":false},{"pmid":"39523437","id":"PMC_39523437","title":"Novel variants in DNAH9 are present in two infertile patients with severe asthenospermia.","date":"2024","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/39523437","citation_count":3,"is_preprint":false},{"pmid":"34008076","id":"PMC_34008076","title":"Whole-exome sequencing reveals a combination of extremely rare single-nucleotide polymorphism of DNAH9 and RSPH1 genes in a Japanese fetus with situs viscerum inversus.","date":"2021","source":"Medical molecular morphology","url":"https://pubmed.ncbi.nlm.nih.gov/34008076","citation_count":3,"is_preprint":false},{"pmid":"40376972","id":"PMC_40376972","title":"Novel compound heterozygous mutation in DNAH9 causes complex congenital heart disease.","date":"2025","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/40376972","citation_count":1,"is_preprint":false},{"pmid":"40065384","id":"PMC_40065384","title":"DNAH9 variants in children with post-infectious bronchiolitis/bronchitis obliterans.","date":"2025","source":"Orphanet journal of rare diseases","url":"https://pubmed.ncbi.nlm.nih.gov/40065384","citation_count":1,"is_preprint":false},{"pmid":"35116053","id":"PMC_35116053","title":"Fetal Congenital Heart Disease Caused by Compound Heterozygous Mutations in the DNAH9 Gene: A Case Report.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35116053","citation_count":1,"is_preprint":false},{"pmid":"26377939","id":"PMC_26377939","title":"Characterization and genomic structure of Dnah9, and its roles in nodal signaling pathways in the Japanese flounder (Paralichthys olivaceus).","date":"2015","source":"Fish physiology and biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26377939","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.07.06.25330330","title":"Spatial and single-cell transcriptomics landscape of adenomyosis","date":"2025-07-07","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.06.25330330","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10051,"output_tokens":1976,"usd":0.029896,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8930,"output_tokens":2624,"usd":0.055125,"stage2_stop_reason":"end_turn"},"total_usd":0.085021,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2005,\n      \"finding\": \"DNAH5 and DNAH9 show distinct regional distribution along the ciliary axoneme in normal human respiratory epithelial cells, indicating the existence of at least two distinct outer dynein arm (ODA) types. DNAH5 localizes along the full axoneme while DNAH9 has a different regional distribution, suggesting they form part of different ODA subtypes.\",\n      \"method\": \"High-resolution immunofluorescence imaging with specific antibodies in human respiratory epithelial and sperm cells\",\n      \"journal\": \"American journal of respiratory and critical care medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct subcellular localization by immunofluorescence with functional consequence (ODA typing), single lab but applied to multiple patient and control samples\",\n      \"pmids\": [\"15750039\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"DNAH9 encodes a 4486 amino acid axonemal beta heavy chain dynein consisting of an N-terminal stem and a globular C-terminus containing four P-loops that constitute the motor domain, with ATPase activity coupled to conformational changes driving cilia and flagella bending.\",\n      \"method\": \"cDNA cloning, RT-PCR, 5' RACE, cDNA library screening, genomic sequencing; protein domain analysis showing homology to sea urchin axonemal beta heavy chain dyneins (67% identity)\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — full cDNA/protein sequence determination with domain identification, single lab but comprehensive molecular characterization\",\n      \"pmids\": [\"11247663\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"DNAH9 and its partner heavy chain DNAH5 co-localize to type 2 ODAs of the distal cilium. Loss of DNAH9 (due to biallelic mutations) causes loss of DNAH9/DNAH5-containing type 2 ODAs restricted to the distal cilia region, conferring reduced beating frequency with a subtle beating pattern defect affecting the motility of the distal cilia portion.\",\n      \"method\": \"Immunofluorescence localization, 3D electron tomography ultrastructural studies, high-speed video microscopy, next-generation sequencing; Paramecium DNAH9 knockdown as functional confirmation\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods (immunofluorescence, 3D electron tomography, functional motility assay, cross-species knockdown), replicated across multiple patients\",\n      \"pmids\": [\"30471717\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"DNAH9 interacts with CCDC114 and GAS8 (as shown by co-immunoprecipitation), and loss of DNAH9 (knockdown in mice) diminishes the protein levels of CCDC114 and GAS8.\",\n      \"method\": \"Co-immunoprecipitation, immunostaining, western blot in Dnah9 knockdown mice\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — reciprocal binding shown by co-IP with protein level consequences, single lab with multiple methods\",\n      \"pmids\": [\"35729109\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Dnah9 knockout in zebrafish disturbs cardiac left-right patterning without affecting ciliogenesis in Kupffer's vesicle, and Dnah9 loss in a knockout mouse model leads to compromised cardiac function.\",\n      \"method\": \"dnah9 morpholino knockdown in zebrafish; Dnah9 knockout C57BL/6n mouse model with cardiac function assessment\",\n      \"journal\": \"Human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic loss-of-function in two model organisms with specific phenotypic readouts, single lab\",\n      \"pmids\": [\"35050399\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"DNAH9 protein is expressed in sperm tails, and loss-of-function variants in DNAH9 lead to significantly decreased DNAH9 mRNA and protein in sperm, causing outer dynein arm defects in sperm axoneme and severe asthenozoospermia without respiratory symptoms, establishing DNAH9 as required for flagellar motility.\",\n      \"method\": \"Whole exome sequencing, Sanger sequencing, TEM of sperm ultrastructure, qRT-PCR, immunofluorescence staining of sperm\",\n      \"journal\": \"Reproductive biology and endocrinology : RB&E\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — multiple complementary methods (TEM, immunofluorescence, expression analysis) in patient sperm, single lab\",\n      \"pmids\": [\"33610189\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Biallelic DNAH9 variants cause loss of outer dynein arms in sperm axoneme cross-sections and reduce expression of flagellar ultrastructure-related proteins DNAI1, DNAH1, and DNAH10, demonstrating that DNAH9 is required for proper assembly or stability of the outer dynein arm complex in flagella.\",\n      \"method\": \"Transmission electron microscopy of sperm axoneme, immunofluorescence showing reduced DNAI1, DNAH1, and DNAH10 expression in DNAH9 variant patients\",\n      \"journal\": \"Journal of human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — TEM ultrastructure plus immunofluorescence of multiple ODA components, single lab\",\n      \"pmids\": [\"39523437\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"A novel DNAH9 splice-site mutation (c.3743+1G>T) leads to abnormal splicing, as demonstrated by minigene analysis, establishing that correct splicing of DNAH9 pre-mRNA is required for functional protein production.\",\n      \"method\": \"Minigene splicing assay, in silico splice prediction, Sanger sequencing\",\n      \"journal\": \"Molecular medicine reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — minigene assay in a single case report, no functional protein rescue experiment\",\n      \"pmids\": [\"40376972\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DNAH9 is an axonemal beta heavy chain dynein (4486 aa) with an N-terminal stem and a C-terminal motor domain containing four P-loops for ATPase activity; it localizes specifically to type 2 outer dynein arms (ODAs) of the distal ciliary axoneme together with DNAH5, where it is required for normal cilia beating frequency and distal cilium motility, interacts with ODA-associated proteins CCDC114 and GAS8 and is required for their stability, and also functions in sperm flagella where its loss disrupts ODA assembly and reduces motility of co-dependent ODA components (DNAI1, DNAH1, DNAH10); loss of DNAH9 in vivo causes defective left-right patterning and compromised cardiac function.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DNAH9 is an axonemal beta heavy chain dynein that powers ciliary and flagellar beating, encoding a 4486-residue protein with an N-terminal stem and a C-terminal globular motor domain bearing four P-loops whose ATPase activity drives the conformational changes underlying axonemal bending [#1]. Within motile cilia DNAH9 marks a distinct outer dynein arm (ODA) subtype: together with its partner heavy chain DNAH5 it occupies type 2 ODAs restricted to the distal ciliary axoneme, and biallelic loss removes these distal ODAs, lowering beat frequency and disrupting motility of the distal cilium [#0, #2]. DNAH9 physically associates with the ODA-related proteins CCDC114 and GAS8 and is required to maintain their protein levels, linking it to ODA docking and stability [#3]. The same dependency operates in sperm flagella, where DNAH9 is expressed in the tail and its loss causes ODA defects with reduced levels of co-assembled components DNAI1, DNAH1 and DNAH10, producing severe asthenozoospermia [#5, #6]. In vivo, DNAH9 loss disturbs cardiac left-right patterning and compromises cardiac function [#4].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Establishing the molecular identity of DNAH9 was the prerequisite for any functional study; cloning defined it as a full-length axonemal beta heavy chain dynein with a defined motor architecture.\",\n      \"evidence\": \"cDNA cloning, RACE, and protein domain analysis revealing four P-loops and homology to sea urchin axonemal beta heavy chains\",\n      \"pmids\": [\"11247663\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"ATPase activity inferred from domain homology, not directly measured\", \"no structural model of the motor domain\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"It was unknown whether all ciliary ODAs were equivalent; differential axonemal distribution of DNAH9 versus DNAH5 revealed that at least two distinct ODA subtypes exist.\",\n      \"evidence\": \"High-resolution immunofluorescence of DNAH5 and DNAH9 in human respiratory epithelial and sperm cells\",\n      \"pmids\": [\"15750039\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"molecular basis of regional targeting unresolved\", \"functional difference between ODA subtypes not yet tested\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"The functional role of the distal ODA subtype was undefined; loss-of-function in patients pinned DNAH9/DNAH5 type 2 ODAs to distal-cilium motility and beat frequency.\",\n      \"evidence\": \"Immunofluorescence, 3D electron tomography, high-speed video microscopy in patients plus Paramecium knockdown\",\n      \"pmids\": [\"30471717\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"does not resolve how the type 2 ODA is targeted distally\", \"mechanism coupling distal ODA loss to the subtle beat defect not detailed\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Whether DNAH9 acted in sperm as in respiratory cilia was unclear; patient analysis showed it is required for flagellar ODA integrity and motility, causing asthenozoospermia without respiratory disease.\",\n      \"evidence\": \"Whole exome sequencing, TEM of sperm ultrastructure, qRT-PCR and immunofluorescence of patient sperm\",\n      \"pmids\": [\"33610189\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"tissue-specific phenotype (sperm vs airway) mechanism not explained\", \"single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"The basis of DNAH9's role in ODA architecture was unknown; co-IP and knockdown defined direct partners CCDC114 and GAS8 and showed DNAH9 is needed to stabilize them.\",\n      \"evidence\": \"Co-immunoprecipitation, immunostaining and western blot in Dnah9 knockdown mice\",\n      \"pmids\": [\"35729109\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"direct versus indirect binding not distinguished\", \"stoichiometry and assembly order within the ODA undefined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"The organismal consequence of DNAH9 loss was untested; model-organism knockouts established a requirement in left-right patterning and cardiac function distinct from ciliogenesis itself.\",\n      \"evidence\": \"dnah9 morpholino knockdown in zebrafish and Dnah9 knockout mouse with cardiac assessment\",\n      \"pmids\": [\"35050399\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"ciliogenesis in Kupffer's vesicle unaffected, so the motility defect driving laterality is not localized\", \"cardiac phenotype mechanism not dissected\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Whether DNAH9 loss propagates to other ODA subunits was open; reduced DNAI1, DNAH1 and DNAH10 in patient sperm showed DNAH9 is required for assembly/stability of the broader ODA complex in flagella.\",\n      \"evidence\": \"TEM of sperm axoneme and immunofluorescence of multiple ODA components in patients\",\n      \"pmids\": [\"39523437\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"direct interaction with the reduced components not demonstrated\", \"assembly hierarchy not established\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A specific splice variant's pathogenicity was uncharacterized; minigene analysis confirmed that correct DNAH9 pre-mRNA splicing is required for functional protein.\",\n      \"evidence\": \"Minigene splicing assay and in silico prediction in a single case report\",\n      \"pmids\": [\"40376972\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"no functional protein rescue experiment\", \"single case report\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How DNAH9-containing type 2 ODAs are specifically targeted to the distal axoneme, and the structural basis of its motor activity, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"no structure of the DNAH9 motor domain\", \"distal-targeting mechanism unknown\", \"direct ATPase/motility reconstitution not reported\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003774\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [0, 2, 5]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [2, 6]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"complexes\": [\"outer dynein arm\"],\n    \"partners\": [\"DNAH5\", \"CCDC114\", \"GAS8\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}