{"gene":"WNT8A","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2001,"finding":"WNT8A encodes a 351-amino-acid secreted polypeptide with an N-terminal signal peptide, three N-linked glycosylation sites, and 22 conserved cysteine residues characteristic of the WNT family, and activates the WNT-beta-catenin-TCF signaling pathway (inferred from its homology to Xenopus wnt-8, the most potent activator of this pathway in axis duplication assays).","method":"Molecular cloning, sequence analysis, structural characterization","journal":"International journal of oncology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — structural inference from sequence analysis and homology, no direct functional assay of human WNT8A protein activity reported in this abstract","pmids":["11408932"],"is_preprint":false},{"year":2014,"finding":"Wnt8a is post-translationally modified by lipid adducts; conserved residues required for lipid modification regulate Wnt8a distribution in producing cell membranes and filopodia, as well as its localization to membrane-associated punctate structures on donor cell filopodia and Frizzled receptor-containing clusters on signal-receiving cells in living zebrafish embryos.","method":"Live fluorescence imaging of fluorescently tagged Wnt8a in zebrafish embryos; in vitro and in vivo signaling assays with conserved-residue mutants","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live imaging plus mutagenesis of conserved residues in two complementary assay systems, single lab","pmids":["24427298"],"is_preprint":false},{"year":2014,"finding":"Conserved Wnt8a residues differentially regulate cell-autonomous versus non-cell-autonomous signaling activity and secretion, as shown by comparing non-signaling Wnt8a variants in producing-cell membrane/filopodial distribution versus receiving-tissue distribution assays.","method":"Mutagenesis of conserved residues; in vitro and in vivo signaling and secretion assays in zebrafish","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis combined with functional in vitro/in vivo assays, single lab","pmids":["24427298"],"is_preprint":false},{"year":2010,"finding":"FGF3 (and FGF4 but not FGF10) signaling is required upstream of Wnt8a expression in the hindbrain; chick explant assays showed FGF3 or FGF4 were sufficient to induce Wnt8a, placing Wnt8a downstream of FGF signaling in the pathway leading to otic placode induction.","method":"Mouse genetic knockouts (Fgf3−/−; Fgf10−/− double mutants), in situ hybridization, chick explant FGF treatment assays","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with double-mutant embryos plus exogenous ligand rescue in chick explants, replicated across two species","pmids":["20171206"],"is_preprint":false},{"year":2011,"finding":"Spry1 and Spry2 (FGF pathway antagonists) limit Wnt8a expression domain in the hindbrain; loss of Spry1/2 expands Wnt8a expression and otic placode size, and reducing Fgf10 gene dosage rescues both phenotypes, establishing that FGF signaling positively regulates Wnt8a through a Sprouty-controlled mechanism.","method":"Compound Spry1/Spry2 knockout mice; genetic rescue by Fgf10 dosage reduction; in situ hybridization","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with compound knockouts and dosage-sensitive rescue experiments","pmids":["21362415"],"is_preprint":false},{"year":2012,"finding":"Wnt8a expression in zebrafish is under biphasic transcriptional control: an early phase (phase I) depends on Nodal signaling activating a margin-specific enhancer together with transcription factor Zbtb4 and a distal regulatory region; a late phase (phase II) requires No tail (Ntl/Brachyury) regulation of the same margin enhancer in the context of the proximal regulatory region.","method":"Transgenic reporter (wnt8a:PAC-EGFP) loss-of-function analysis; cis-regulatory dissection with proximal and distal regulatory region constructs in zebrafish","journal":"Developmental dynamics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cis-regulatory dissection with transgenic reporters and genetic loss-of-function, single lab","pmids":["22473868","21384472"],"is_preprint":false},{"year":2012,"finding":"Wnt8a expression in the mouse hindbrain is dependent on Fgf3 (serial regulation), but Wnt8a by itself is not essential for otic placode specification; however, Wnt8a and Fgf3 are redundantly required for Fgf15 expression in the hindbrain, and Wnt8a and Wnt1 are redundantly required for dorsal otic vesicle morphogenesis.","method":"Mouse Wnt8a and Fgf3 single and compound knockouts; in situ hybridization for otic and hindbrain markers","journal":"Mechanisms of development","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis using single and compound knockouts with defined molecular readouts","pmids":["23041177"],"is_preprint":false},{"year":2013,"finding":"Post-transcriptional regulation of wnt8a by its 3' UTRs is essential for normal zebrafish axis development: both UTR1 and UTR2 suppress reporter expression in cis, and UTR2 contains a 6-base sequence complementary to the miR-430 seed; a target-protector morpholino blocking miR-430 access stabilizes wnt8a mRNAs and produces gain-of-function axis phenotypes.","method":"Transgenic and transient reporter assays with UTR deletions/mutations; target-protector morpholino; rescue assays attributing specific functions to wnt8a.1 and wnt8a.2 proteins","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (reporter assays, mutagenesis of miR-430 seed complement, morpholino target protector, in vivo rescue) in single rigorous study","pmids":["24333179"],"is_preprint":false},{"year":2015,"finding":"The chromatin remodeling protein Bptf interacts physically and functionally with phospho-Smad2 (activated by non-Nodal TGF-β signaling) to directly bind and activate the wnt8a promoter by recruiting the NURF remodeling complex; inhibition of bptf or TGF-β signaling increases nucleosome density on the wnt8a promoter.","method":"Co-immunoprecipitation of Bptf with p-Smad2; chromatin immunoprecipitation of Bptf/Smad2 on wnt8a promoter; nucleosome occupancy assays; morpholino knockdown with in situ hybridization readouts in zebrafish","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — physical interaction (Co-IP), direct promoter binding (ChIP), nucleosome remodeling assay, and loss-of-function in vivo, single lab with multiple orthogonal methods","pmids":["26041917"],"is_preprint":false},{"year":2015,"finding":"In mice, Wnt8a and Wnt3a cooperate in the axial stem cell niche to maintain Fgf8 expression and prevent premature Sox2 upregulation, required for posterior body axis extension; Wnt8a expression is restricted caudally by retinoic acid (RA) signaling, and the Wnt8a locus contains an upstream RA response element that binds RA receptors.","method":"Mouse Wnt8a−/−, Wnt3a−/−, and double-mutant analysis; in situ hybridization for Fgf8 and Sox2; RA response element identification with receptor binding","journal":"Developmental dynamics","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with single and double mutants plus RA response element functional characterization","pmids":["25809880"],"is_preprint":false},{"year":2017,"finding":"In zebrafish, wnt8a expressed in intermediate mesoderm expands the renal progenitor pool by promoting proliferation (EdU incorporation assay) without affecting apoptosis; canonical Wnt pathway agonist BIO can rescue the reduced renal progenitor pool in wnt8a morphants.","method":"Morpholino knockdown of wnt8a; EdU proliferation assay; pharmacological rescue with canonical Wnt agonist BIO; cellular phenotyping at 24 hpf","journal":"Developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with specific proliferation readout and pharmacological rescue, single lab","pmids":["28359809"],"is_preprint":false},{"year":2017,"finding":"Maternal wnt8a is dispensable for initial dorsal axis determination in zebrafish; zygotic wnt8a ORF1 and ORF2 act redundantly for ventrolateral and posterior tissue formation; maternal wnt8a cooperates with zygotic wnt8a for these processes but is not the primary dorsal determinant.","method":"TALEN-mediated generation of wnt8a ORF1 and ORF2 mutants; germ-line replacement to generate maternal, zygotic, and maternal-zygotic mutants; phenotypic analysis","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — rigorous genetic dissection using TALEN knockouts and germ-line replacement with defined phenotypic readouts","pmids":["29208373"],"is_preprint":false},{"year":2025,"finding":"During neurite regrowth of injured cortical neurons, Wnt8a transcription is regulated through enhancer-promoter looping: enhancer regions En8 and En14 (located ~1.7 Mb upstream) physically contact the Wnt8a promoter via chromatin loops (detected by chromatin conformation capture); these regions show upregulated H3K4me1 modification and enhanced eRNA expression during neurite regrowth.","method":"Chromatin conformation capture (3C); H3K27ac/H3K4me1 ChIP; eRNA expression profiling; enhancer-reporter assays","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — chromatin conformation capture plus histone mark ChIP and reporter assays, single lab, no replication","pmids":["40072048"],"is_preprint":false}],"current_model":"WNT8A is a lipid-modified, glycosylated secreted ligand that activates canonical WNT-β-catenin-TCF signaling; its expression is transcriptionally controlled by upstream FGF signaling (via FGF3/FGF4 inducing Wnt8a in the hindbrain through Sprouty-regulated FGF activity), by a biphasic Nodal→Zbtb4 and Ntl/Brachyury cis-regulatory program, by Bptf-pSmad2-NURF-mediated chromatin remodeling at its promoter, and by retinoic acid receptors binding a caudal RA response element; post-transcriptionally, miR-430 targets conserved sequences in its 3' UTRs to fine-tune mRNA stability; the mature protein localizes to filopodial puncta on donor cells and Frizzled receptor clusters on receiving cells, with conserved residues for lipid modification controlling both its distribution and signaling range; in vivo, WNT8A cooperates with WNT3A to maintain FGF8 expression and axial stem cell identity, acts redundantly with WNT1 for dorsal otic vesicle morphogenesis, and promotes proliferative expansion of renal progenitors via canonical WNT signaling."},"narrative":{"mechanistic_narrative":"WNT8A is a lipid-modified, glycosylated secreted WNT-family ligand that activates canonical WNT-β-catenin-TCF signaling and patterns posterior and otic tissues during development [PMID:11408932, PMID:29208373]. Conserved residues required for lipid modification govern the protein's distribution across producing-cell membranes and filopodia, its localization to punctate structures on donor-cell filopodia and to Frizzled receptor clusters on receiving cells, and the separable cell-autonomous versus non-cell-autonomous reach of its signaling activity [PMID:24427298]. Its expression is tightly controlled at multiple levels: FGF signaling acts upstream to induce and spatially restrict Wnt8a in the hindbrain, with FGF3/FGF4 sufficient to induce it and Sprouty antagonists limiting its domain [PMID:20171206, PMID:21362415]; a biphasic transcriptional program drives margin-specific expression through Nodal-activated Zbtb4 and a distal enhancer in an early phase and No tail/Brachyury through a proximal element in a late phase [PMID:22473868, PMID:21384472]; Bptf bound to phospho-Smad2 recruits the NURF remodeling complex to activate the promoter [PMID:26041917]; and retinoic acid receptors binding an upstream RA response element confine its expression caudally [PMID:25809880]. Post-transcriptionally, the wnt8a 3' UTRs suppress expression in cis, with a miR-430 seed-complementary sequence controlling mRNA stability to fine-tune axis development [PMID:24333179]. Functionally, WNT8A cooperates with WNT3A to maintain Fgf8 and axial stem cell identity for posterior body extension [PMID:25809880], acts redundantly with WNT1 for dorsal otic vesicle morphogenesis [PMID:23041177], and drives proliferative expansion of renal progenitors through the canonical pathway [PMID:28359809].","teleology":[{"year":2001,"claim":"Established WNT8A as a canonical WNT-family secreted ligand by molecular identification of its conserved structural hallmarks, framing it as a likely activator of β-catenin-TCF signaling.","evidence":"Molecular cloning and sequence/structural analysis with homology inference to Xenopus wnt-8","pmids":["11408932"],"confidence":"Low","gaps":["Activity inferred from homology, not measured directly for human WNT8A protein","No experimental signaling assay reported","No partner or receptor identified"]},{"year":2010,"claim":"Placed Wnt8a downstream of FGF signaling in otic placode induction, answering how this ligand is positioned within an upstream patterning cascade.","evidence":"Mouse Fgf3/Fgf10 knockouts, in situ hybridization, and chick explant FGF treatment","pmids":["20171206"],"confidence":"High","gaps":["Direct transcriptional mechanism of FGF-to-Wnt8a induction not resolved","FGF receptor mediating induction not defined"]},{"year":2011,"claim":"Showed FGF signaling positively shapes the Wnt8a expression domain through Sprouty antagonists, defining how its spatial boundary is set.","evidence":"Compound Spry1/Spry2 knockout mice with Fgf10 dosage-reduction rescue and in situ hybridization","pmids":["21362415"],"confidence":"High","gaps":["Direct cis-regulatory targets of FGF/Sprouty at the Wnt8a locus not mapped"]},{"year":2012,"claim":"Dissected a biphasic cis-regulatory program controlling wnt8a transcription, distinguishing early Nodal/Zbtb4-driven from late Brachyury-driven phases through distinct regulatory regions.","evidence":"Transgenic wnt8a:PAC-EGFP reporters and cis-regulatory dissection with proximal/distal constructs in zebrafish","pmids":["22473868","21384472"],"confidence":"Medium","gaps":["Direct binding of Zbtb4 and Ntl to the enhancer not biochemically confirmed","Single-lab cis-regulatory analysis"]},{"year":2012,"claim":"Resolved the in vivo requirement for Wnt8a in otic development, showing it is non-essential alone but redundant with Fgf3 for Fgf15 and with Wnt1 for dorsal otic morphogenesis.","evidence":"Mouse Wnt8a and Fgf3 single and compound knockouts with otic/hindbrain marker readouts","pmids":["23041177"],"confidence":"High","gaps":["Molecular basis of Wnt8a/Wnt1 redundancy not defined","Receiving-cell receptors in otic vesicle not identified"]},{"year":2013,"claim":"Demonstrated post-transcriptional control of wnt8a via its 3' UTRs and miR-430, establishing how ligand dosage is buffered to safeguard axis development.","evidence":"Reporter assays with UTR deletions, miR-430 seed mutagenesis, target-protector morpholino, and in vivo rescue in zebrafish","pmids":["24333179"],"confidence":"High","gaps":["Quantitative contribution of miR-430 relative to other UTR elements not fully separated"]},{"year":2014,"claim":"Connected lipid modification of Wnt8a to its physical distribution and signaling range, showing conserved residues control filopodial puncta and Frizzled-cluster localization and separate cell-autonomous from non-cell-autonomous activity.","evidence":"Live imaging of fluorescently tagged Wnt8a and mutagenesis of conserved residues in zebrafish plus in vitro signaling assays","pmids":["24427298"],"confidence":"Medium","gaps":["Identity of the lipid-modifying enzyme not addressed in the finding","Single-lab observation"]},{"year":2015,"claim":"Identified a direct chromatin-level activation mechanism in which Bptf-phospho-Smad2 recruits NURF to remodel the wnt8a promoter, linking non-Nodal TGF-β input to expression.","evidence":"Co-IP of Bptf with p-Smad2, ChIP on the wnt8a promoter, nucleosome occupancy assays, and morpholino knockdown in zebrafish","pmids":["26041917"],"confidence":"High","gaps":["TGF-β ligand activating p-Smad2 in this context not specified","Single lab"]},{"year":2015,"claim":"Defined an in vivo role for Wnt8a in the axial stem cell niche cooperating with Wnt3a to maintain Fgf8 and posterior identity, and showed retinoic acid receptors confine its expression caudally via an upstream RARE.","evidence":"Mouse Wnt8a/Wnt3a single and double mutants, marker in situ hybridization, and RARE receptor-binding characterization","pmids":["25809880"],"confidence":"High","gaps":["Direct mechanism of Wnt8a/Wnt3a cooperation on Fgf8 not resolved at molecular level"]},{"year":2017,"claim":"Extended Wnt8a function to renal progenitor biology, showing it expands the progenitor pool via canonical-pathway-dependent proliferation rather than survival.","evidence":"wnt8a morpholino knockdown, EdU proliferation assay, and BIO canonical-Wnt agonist rescue in zebrafish","pmids":["28359809"],"confidence":"Medium","gaps":["Downstream proliferative effectors not identified","Single-lab morpholino-based loss-of-function"]},{"year":2017,"claim":"Disentangled maternal versus zygotic and ORF1/ORF2 contributions, showing maternal wnt8a is dispensable for dorsal axis determination while zygotic ORFs act redundantly in ventrolateral/posterior patterning.","evidence":"TALEN knockouts and germ-line replacement generating maternal, zygotic, and maternal-zygotic wnt8a mutants in zebrafish","pmids":["29208373"],"confidence":"High","gaps":["Functional distinction between ORF1 and ORF2 proteins beyond redundancy not detailed"]},{"year":2025,"claim":"Revealed long-range enhancer-promoter looping controlling Wnt8a transcription during neurite regrowth, implicating it in injured-neuron responses.","evidence":"Chromatin conformation capture, H3K27ac/H3K4me1 ChIP, eRNA profiling, and enhancer-reporter assays","pmids":["40072048"],"confidence":"Medium","gaps":["Functional requirement of En8/En14 for neurite regrowth not established by deletion","Single lab, no replication"]},{"year":null,"claim":"How human WNT8A protein engages specific Frizzled receptors and which downstream effectors mediate its tissue-specific outputs remain undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["No direct biochemical receptor-binding data for human WNT8A in the corpus","Structural model of ligand-receptor engagement not established","Disease association not addressed in the timeline"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[0,1,2]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[1,2]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,10]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[6,9,11]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[5,8,9,12]}],"complexes":[],"partners":["FZD"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9H1J5","full_name":"Protein Wnt-8a","aliases":["Protein Wnt-8d"],"length_aa":351,"mass_kda":38.8,"function":"Ligand for members of the frizzled family of seven transmembrane receptors. Plays a role in embryonic patterning","subcellular_location":"Secreted, extracellular space, extracellular matrix; Secreted","url":"https://www.uniprot.org/uniprotkb/Q9H1J5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/WNT8A","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/WNT8A","total_profiled":1310},"omim":[{"mim_id":"614913","title":"TRAB DOMAIN-CONTAINING PROTEIN 2B; TRABD2B","url":"https://www.omim.org/entry/614913"},{"mim_id":"614912","title":"TRAB DOMAIN-CONTAINING PROTEIN 2A; TRABD2A","url":"https://www.omim.org/entry/614912"},{"mim_id":"606360","title":"WINGLESS-TYPE MMTV INTEGRATION SITE FAMILY, MEMBER 8A; WNT8A","url":"https://www.omim.org/entry/606360"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Not detected","tissue_distribution":"Not detected","driving_tissues":[],"url":"https://www.proteinatlas.org/search/WNT8A"},"hgnc":{"alias_symbol":["WNT8D"],"prev_symbol":[]},"alphafold":{"accession":"Q9H1J5","domains":[{"cath_id":"-","chopping":"11-227_236-259","consensus_level":"high","plddt":84.2478,"start":11,"end":259},{"cath_id":"3.30.2460.20","chopping":"271-341","consensus_level":"medium","plddt":91.5593,"start":271,"end":341}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H1J5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H1J5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H1J5-F1-predicted_aligned_error_v6.png","plddt_mean":83.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=WNT8A","jax_strain_url":"https://www.jax.org/strain/search?query=WNT8A"},"sequence":{"accession":"Q9H1J5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H1J5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H1J5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H1J5"}},"corpus_meta":[{"pmid":"11408932","id":"PMC_11408932","title":"Molecular cloning and characterization of human WNT8A.","date":"2001","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/11408932","citation_count":97,"is_preprint":false},{"pmid":"20171206","id":"PMC_20171206","title":"FGF signaling regulates otic placode induction and refinement by controlling both ectodermal target genes and hindbrain Wnt8a.","date":"2010","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/20171206","citation_count":75,"is_preprint":false},{"pmid":"24427298","id":"PMC_24427298","title":"Dynamic association with donor cell filopodia and lipid-modification are essential features of Wnt8a during patterning of the zebrafish neuroectoderm.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24427298","citation_count":50,"is_preprint":false},{"pmid":"11956596","id":"PMC_11956596","title":"Expression and regulation of WNT8A and WNT8B mRNAs in human tumor cell lines: up-regulation of WNT8B mRNA by beta-estradiol in MCF-7 cells, and down-regulation of WNT8A and WNT8B mRNAs by retinoic acid in NT2 cells.","date":"2002","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/11956596","citation_count":46,"is_preprint":false},{"pmid":"21362415","id":"PMC_21362415","title":"Sprouty1 and Sprouty2 limit both the size of the otic placode and hindbrain Wnt8a by antagonizing FGF signaling.","date":"2011","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/21362415","citation_count":37,"is_preprint":false},{"pmid":"15754011","id":"PMC_15754011","title":"Comparative genomics on Wnt8a and Wnt8b genes.","date":"2005","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/15754011","citation_count":35,"is_preprint":false},{"pmid":"25809880","id":"PMC_25809880","title":"Wnt8a and Wnt3a cooperate in the axial stem cell niche to promote mammalian body axis extension.","date":"2015","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/25809880","citation_count":32,"is_preprint":false},{"pmid":"29208373","id":"PMC_29208373","title":"Roles of maternal wnt8a transcripts in axis formation in zebrafish.","date":"2017","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/29208373","citation_count":30,"is_preprint":false},{"pmid":"33687475","id":"PMC_33687475","title":"lncRNA Ttc3-209 Promotes the Apoptosis of Retinal Ganglion Cells in Retinal Ischemia Reperfusion Injury by Targeting the miR-484/Wnt8a Axis.","date":"2021","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/33687475","citation_count":27,"is_preprint":false},{"pmid":"26041917","id":"PMC_26041917","title":"The Chromatin Remodeling Protein Bptf Promotes Posterior Neuroectodermal Fate by Enhancing Smad2-Activated wnt8a Expression.","date":"2015","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/26041917","citation_count":19,"is_preprint":false},{"pmid":"23041177","id":"PMC_23041177","title":"Roles of Wnt8a during formation and patterning of the mouse inner ear.","date":"2012","source":"Mechanisms of development","url":"https://pubmed.ncbi.nlm.nih.gov/23041177","citation_count":18,"is_preprint":false},{"pmid":"24333179","id":"PMC_24333179","title":"Post-transcriptional regulation of wnt8a is essential to zebrafish axis development.","date":"2013","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/24333179","citation_count":12,"is_preprint":false},{"pmid":"22473868","id":"PMC_22473868","title":"Biphasic wnt8a expression is achieved through interactions of multiple regulatory inputs.","date":"2012","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/22473868","citation_count":12,"is_preprint":false},{"pmid":"37073259","id":"PMC_37073259","title":"Wnt8a is one of the candidate genes that play essential roles in the elongation of the seahorse prehensile tail.","date":"2021","source":"Marine life science & technology","url":"https://pubmed.ncbi.nlm.nih.gov/37073259","citation_count":8,"is_preprint":false},{"pmid":"28359809","id":"PMC_28359809","title":"Wnt8a expands the pool of embryonic kidney progenitors in zebrafish.","date":"2017","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/28359809","citation_count":8,"is_preprint":false},{"pmid":"23836442","id":"PMC_23836442","title":"Polymorphisms and expression of the WNT8A gene in Hirschsprung's disease.","date":"2013","source":"International journal of molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/23836442","citation_count":5,"is_preprint":false},{"pmid":"21384472","id":"PMC_21384472","title":"A transgenic wnt8a:PAC reporter reveals biphasic regulation of vertebrate mesoderm development.","date":"2011","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/21384472","citation_count":5,"is_preprint":false},{"pmid":"28947701","id":"PMC_28947701","title":"Effects of genetic variants of the bovine WNT8A gene on nine important growth traits in beef cattle.","date":"2017","source":"Journal of genetics","url":"https://pubmed.ncbi.nlm.nih.gov/28947701","citation_count":3,"is_preprint":false},{"pmid":"40072048","id":"PMC_40072048","title":"The Enhancer-Promoter-Mediated Wnt8a Transcription During Neurite Regrowth of Injured Cortical Neurons.","date":"2025","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/40072048","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":11216,"output_tokens":3501,"usd":0.043082,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11008,"output_tokens":3808,"usd":0.07512,"stage2_stop_reason":"end_turn"},"total_usd":0.118202,"stage1_batch_id":"msgbatch_01UT1AahFPCAyn2uVweS7A9z","stage2_batch_id":"msgbatch_01HuKWtKNT4Pqj1bc8eEP5RV","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2001,\n      \"finding\": \"WNT8A encodes a 351-amino-acid secreted polypeptide with an N-terminal signal peptide, three N-linked glycosylation sites, and 22 conserved cysteine residues characteristic of the WNT family, and activates the WNT-beta-catenin-TCF signaling pathway (inferred from its homology to Xenopus wnt-8, the most potent activator of this pathway in axis duplication assays).\",\n      \"method\": \"Molecular cloning, sequence analysis, structural characterization\",\n      \"journal\": \"International journal of oncology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — structural inference from sequence analysis and homology, no direct functional assay of human WNT8A protein activity reported in this abstract\",\n      \"pmids\": [\"11408932\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Wnt8a is post-translationally modified by lipid adducts; conserved residues required for lipid modification regulate Wnt8a distribution in producing cell membranes and filopodia, as well as its localization to membrane-associated punctate structures on donor cell filopodia and Frizzled receptor-containing clusters on signal-receiving cells in living zebrafish embryos.\",\n      \"method\": \"Live fluorescence imaging of fluorescently tagged Wnt8a in zebrafish embryos; in vitro and in vivo signaling assays with conserved-residue mutants\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live imaging plus mutagenesis of conserved residues in two complementary assay systems, single lab\",\n      \"pmids\": [\"24427298\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Conserved Wnt8a residues differentially regulate cell-autonomous versus non-cell-autonomous signaling activity and secretion, as shown by comparing non-signaling Wnt8a variants in producing-cell membrane/filopodial distribution versus receiving-tissue distribution assays.\",\n      \"method\": \"Mutagenesis of conserved residues; in vitro and in vivo signaling and secretion assays in zebrafish\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis combined with functional in vitro/in vivo assays, single lab\",\n      \"pmids\": [\"24427298\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"FGF3 (and FGF4 but not FGF10) signaling is required upstream of Wnt8a expression in the hindbrain; chick explant assays showed FGF3 or FGF4 were sufficient to induce Wnt8a, placing Wnt8a downstream of FGF signaling in the pathway leading to otic placode induction.\",\n      \"method\": \"Mouse genetic knockouts (Fgf3−/−; Fgf10−/− double mutants), in situ hybridization, chick explant FGF treatment assays\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with double-mutant embryos plus exogenous ligand rescue in chick explants, replicated across two species\",\n      \"pmids\": [\"20171206\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Spry1 and Spry2 (FGF pathway antagonists) limit Wnt8a expression domain in the hindbrain; loss of Spry1/2 expands Wnt8a expression and otic placode size, and reducing Fgf10 gene dosage rescues both phenotypes, establishing that FGF signaling positively regulates Wnt8a through a Sprouty-controlled mechanism.\",\n      \"method\": \"Compound Spry1/Spry2 knockout mice; genetic rescue by Fgf10 dosage reduction; in situ hybridization\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with compound knockouts and dosage-sensitive rescue experiments\",\n      \"pmids\": [\"21362415\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Wnt8a expression in zebrafish is under biphasic transcriptional control: an early phase (phase I) depends on Nodal signaling activating a margin-specific enhancer together with transcription factor Zbtb4 and a distal regulatory region; a late phase (phase II) requires No tail (Ntl/Brachyury) regulation of the same margin enhancer in the context of the proximal regulatory region.\",\n      \"method\": \"Transgenic reporter (wnt8a:PAC-EGFP) loss-of-function analysis; cis-regulatory dissection with proximal and distal regulatory region constructs in zebrafish\",\n      \"journal\": \"Developmental dynamics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cis-regulatory dissection with transgenic reporters and genetic loss-of-function, single lab\",\n      \"pmids\": [\"22473868\", \"21384472\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Wnt8a expression in the mouse hindbrain is dependent on Fgf3 (serial regulation), but Wnt8a by itself is not essential for otic placode specification; however, Wnt8a and Fgf3 are redundantly required for Fgf15 expression in the hindbrain, and Wnt8a and Wnt1 are redundantly required for dorsal otic vesicle morphogenesis.\",\n      \"method\": \"Mouse Wnt8a and Fgf3 single and compound knockouts; in situ hybridization for otic and hindbrain markers\",\n      \"journal\": \"Mechanisms of development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis using single and compound knockouts with defined molecular readouts\",\n      \"pmids\": [\"23041177\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Post-transcriptional regulation of wnt8a by its 3' UTRs is essential for normal zebrafish axis development: both UTR1 and UTR2 suppress reporter expression in cis, and UTR2 contains a 6-base sequence complementary to the miR-430 seed; a target-protector morpholino blocking miR-430 access stabilizes wnt8a mRNAs and produces gain-of-function axis phenotypes.\",\n      \"method\": \"Transgenic and transient reporter assays with UTR deletions/mutations; target-protector morpholino; rescue assays attributing specific functions to wnt8a.1 and wnt8a.2 proteins\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (reporter assays, mutagenesis of miR-430 seed complement, morpholino target protector, in vivo rescue) in single rigorous study\",\n      \"pmids\": [\"24333179\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"The chromatin remodeling protein Bptf interacts physically and functionally with phospho-Smad2 (activated by non-Nodal TGF-β signaling) to directly bind and activate the wnt8a promoter by recruiting the NURF remodeling complex; inhibition of bptf or TGF-β signaling increases nucleosome density on the wnt8a promoter.\",\n      \"method\": \"Co-immunoprecipitation of Bptf with p-Smad2; chromatin immunoprecipitation of Bptf/Smad2 on wnt8a promoter; nucleosome occupancy assays; morpholino knockdown with in situ hybridization readouts in zebrafish\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — physical interaction (Co-IP), direct promoter binding (ChIP), nucleosome remodeling assay, and loss-of-function in vivo, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"26041917\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"In mice, Wnt8a and Wnt3a cooperate in the axial stem cell niche to maintain Fgf8 expression and prevent premature Sox2 upregulation, required for posterior body axis extension; Wnt8a expression is restricted caudally by retinoic acid (RA) signaling, and the Wnt8a locus contains an upstream RA response element that binds RA receptors.\",\n      \"method\": \"Mouse Wnt8a−/−, Wnt3a−/−, and double-mutant analysis; in situ hybridization for Fgf8 and Sox2; RA response element identification with receptor binding\",\n      \"journal\": \"Developmental dynamics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with single and double mutants plus RA response element functional characterization\",\n      \"pmids\": [\"25809880\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"In zebrafish, wnt8a expressed in intermediate mesoderm expands the renal progenitor pool by promoting proliferation (EdU incorporation assay) without affecting apoptosis; canonical Wnt pathway agonist BIO can rescue the reduced renal progenitor pool in wnt8a morphants.\",\n      \"method\": \"Morpholino knockdown of wnt8a; EdU proliferation assay; pharmacological rescue with canonical Wnt agonist BIO; cellular phenotyping at 24 hpf\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with specific proliferation readout and pharmacological rescue, single lab\",\n      \"pmids\": [\"28359809\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Maternal wnt8a is dispensable for initial dorsal axis determination in zebrafish; zygotic wnt8a ORF1 and ORF2 act redundantly for ventrolateral and posterior tissue formation; maternal wnt8a cooperates with zygotic wnt8a for these processes but is not the primary dorsal determinant.\",\n      \"method\": \"TALEN-mediated generation of wnt8a ORF1 and ORF2 mutants; germ-line replacement to generate maternal, zygotic, and maternal-zygotic mutants; phenotypic analysis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — rigorous genetic dissection using TALEN knockouts and germ-line replacement with defined phenotypic readouts\",\n      \"pmids\": [\"29208373\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"During neurite regrowth of injured cortical neurons, Wnt8a transcription is regulated through enhancer-promoter looping: enhancer regions En8 and En14 (located ~1.7 Mb upstream) physically contact the Wnt8a promoter via chromatin loops (detected by chromatin conformation capture); these regions show upregulated H3K4me1 modification and enhanced eRNA expression during neurite regrowth.\",\n      \"method\": \"Chromatin conformation capture (3C); H3K27ac/H3K4me1 ChIP; eRNA expression profiling; enhancer-reporter assays\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — chromatin conformation capture plus histone mark ChIP and reporter assays, single lab, no replication\",\n      \"pmids\": [\"40072048\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"WNT8A is a lipid-modified, glycosylated secreted ligand that activates canonical WNT-β-catenin-TCF signaling; its expression is transcriptionally controlled by upstream FGF signaling (via FGF3/FGF4 inducing Wnt8a in the hindbrain through Sprouty-regulated FGF activity), by a biphasic Nodal→Zbtb4 and Ntl/Brachyury cis-regulatory program, by Bptf-pSmad2-NURF-mediated chromatin remodeling at its promoter, and by retinoic acid receptors binding a caudal RA response element; post-transcriptionally, miR-430 targets conserved sequences in its 3' UTRs to fine-tune mRNA stability; the mature protein localizes to filopodial puncta on donor cells and Frizzled receptor clusters on receiving cells, with conserved residues for lipid modification controlling both its distribution and signaling range; in vivo, WNT8A cooperates with WNT3A to maintain FGF8 expression and axial stem cell identity, acts redundantly with WNT1 for dorsal otic vesicle morphogenesis, and promotes proliferative expansion of renal progenitors via canonical WNT signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"WNT8A is a lipid-modified, glycosylated secreted WNT-family ligand that activates canonical WNT-\\u03b2-catenin-TCF signaling and patterns posterior and otic tissues during development [#0, #11]. Conserved residues required for lipid modification govern the protein's distribution across producing-cell membranes and filopodia, its localization to punctate structures on donor-cell filopodia and to Frizzled receptor clusters on receiving cells, and the separable cell-autonomous versus non-cell-autonomous reach of its signaling activity [#1, #2]. Its expression is tightly controlled at multiple levels: FGF signaling acts upstream to induce and spatially restrict Wnt8a in the hindbrain, with FGF3/FGF4 sufficient to induce it and Sprouty antagonists limiting its domain [#3, #4]; a biphasic transcriptional program drives margin-specific expression through Nodal-activated Zbtb4 and a distal enhancer in an early phase and No tail/Brachyury through a proximal element in a late phase [#5]; Bptf bound to phospho-Smad2 recruits the NURF remodeling complex to activate the promoter [#8]; and retinoic acid receptors binding an upstream RA response element confine its expression caudally [#9]. Post-transcriptionally, the wnt8a 3' UTRs suppress expression in cis, with a miR-430 seed-complementary sequence controlling mRNA stability to fine-tune axis development [#7]. Functionally, WNT8A cooperates with WNT3A to maintain Fgf8 and axial stem cell identity for posterior body extension [#9], acts redundantly with WNT1 for dorsal otic vesicle morphogenesis [#6], and drives proliferative expansion of renal progenitors through the canonical pathway [#10].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established WNT8A as a canonical WNT-family secreted ligand by molecular identification of its conserved structural hallmarks, framing it as a likely activator of \\u03b2-catenin-TCF signaling.\",\n      \"evidence\": \"Molecular cloning and sequence/structural analysis with homology inference to Xenopus wnt-8\",\n      \"pmids\": [\"11408932\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Activity inferred from homology, not measured directly for human WNT8A protein\", \"No experimental signaling assay reported\", \"No partner or receptor identified\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Placed Wnt8a downstream of FGF signaling in otic placode induction, answering how this ligand is positioned within an upstream patterning cascade.\",\n      \"evidence\": \"Mouse Fgf3/Fgf10 knockouts, in situ hybridization, and chick explant FGF treatment\",\n      \"pmids\": [\"20171206\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct transcriptional mechanism of FGF-to-Wnt8a induction not resolved\", \"FGF receptor mediating induction not defined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Showed FGF signaling positively shapes the Wnt8a expression domain through Sprouty antagonists, defining how its spatial boundary is set.\",\n      \"evidence\": \"Compound Spry1/Spry2 knockout mice with Fgf10 dosage-reduction rescue and in situ hybridization\",\n      \"pmids\": [\"21362415\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct cis-regulatory targets of FGF/Sprouty at the Wnt8a locus not mapped\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Dissected a biphasic cis-regulatory program controlling wnt8a transcription, distinguishing early Nodal/Zbtb4-driven from late Brachyury-driven phases through distinct regulatory regions.\",\n      \"evidence\": \"Transgenic wnt8a:PAC-EGFP reporters and cis-regulatory dissection with proximal/distal constructs in zebrafish\",\n      \"pmids\": [\"22473868\", \"21384472\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding of Zbtb4 and Ntl to the enhancer not biochemically confirmed\", \"Single-lab cis-regulatory analysis\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the in vivo requirement for Wnt8a in otic development, showing it is non-essential alone but redundant with Fgf3 for Fgf15 and with Wnt1 for dorsal otic morphogenesis.\",\n      \"evidence\": \"Mouse Wnt8a and Fgf3 single and compound knockouts with otic/hindbrain marker readouts\",\n      \"pmids\": [\"23041177\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of Wnt8a/Wnt1 redundancy not defined\", \"Receiving-cell receptors in otic vesicle not identified\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Demonstrated post-transcriptional control of wnt8a via its 3' UTRs and miR-430, establishing how ligand dosage is buffered to safeguard axis development.\",\n      \"evidence\": \"Reporter assays with UTR deletions, miR-430 seed mutagenesis, target-protector morpholino, and in vivo rescue in zebrafish\",\n      \"pmids\": [\"24333179\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative contribution of miR-430 relative to other UTR elements not fully separated\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Connected lipid modification of Wnt8a to its physical distribution and signaling range, showing conserved residues control filopodial puncta and Frizzled-cluster localization and separate cell-autonomous from non-cell-autonomous activity.\",\n      \"evidence\": \"Live imaging of fluorescently tagged Wnt8a and mutagenesis of conserved residues in zebrafish plus in vitro signaling assays\",\n      \"pmids\": [\"24427298\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Identity of the lipid-modifying enzyme not addressed in the finding\", \"Single-lab observation\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified a direct chromatin-level activation mechanism in which Bptf-phospho-Smad2 recruits NURF to remodel the wnt8a promoter, linking non-Nodal TGF-\\u03b2 input to expression.\",\n      \"evidence\": \"Co-IP of Bptf with p-Smad2, ChIP on the wnt8a promoter, nucleosome occupancy assays, and morpholino knockdown in zebrafish\",\n      \"pmids\": [\"26041917\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"TGF-\\u03b2 ligand activating p-Smad2 in this context not specified\", \"Single lab\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined an in vivo role for Wnt8a in the axial stem cell niche cooperating with Wnt3a to maintain Fgf8 and posterior identity, and showed retinoic acid receptors confine its expression caudally via an upstream RARE.\",\n      \"evidence\": \"Mouse Wnt8a/Wnt3a single and double mutants, marker in situ hybridization, and RARE receptor-binding characterization\",\n      \"pmids\": [\"25809880\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct mechanism of Wnt8a/Wnt3a cooperation on Fgf8 not resolved at molecular level\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Extended Wnt8a function to renal progenitor biology, showing it expands the progenitor pool via canonical-pathway-dependent proliferation rather than survival.\",\n      \"evidence\": \"wnt8a morpholino knockdown, EdU proliferation assay, and BIO canonical-Wnt agonist rescue in zebrafish\",\n      \"pmids\": [\"28359809\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Downstream proliferative effectors not identified\", \"Single-lab morpholino-based loss-of-function\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Disentangled maternal versus zygotic and ORF1/ORF2 contributions, showing maternal wnt8a is dispensable for dorsal axis determination while zygotic ORFs act redundantly in ventrolateral/posterior patterning.\",\n      \"evidence\": \"TALEN knockouts and germ-line replacement generating maternal, zygotic, and maternal-zygotic wnt8a mutants in zebrafish\",\n      \"pmids\": [\"29208373\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional distinction between ORF1 and ORF2 proteins beyond redundancy not detailed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed long-range enhancer-promoter looping controlling Wnt8a transcription during neurite regrowth, implicating it in injured-neuron responses.\",\n      \"evidence\": \"Chromatin conformation capture, H3K27ac/H3K4me1 ChIP, eRNA profiling, and enhancer-reporter assays\",\n      \"pmids\": [\"40072048\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional requirement of En8/En14 for neurite regrowth not established by deletion\", \"Single lab, no replication\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How human WNT8A protein engages specific Frizzled receptors and which downstream effectors mediate its tissue-specific outputs remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct biochemical receptor-binding data for human WNT8A in the corpus\", \"Structural model of ligand-receptor engagement not established\", \"Disease association not addressed in the timeline\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 10]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [6, 9, 11]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [5, 8, 9, 12]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"FZD\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}