| Claim/Observation | Species/System | Experimental approach | Key quantitative data | Interpretation for function/localization/pathway | Primary citation (with DOI/URL + year) |
|---|---|---|---|---|---|
| *bdh2* knockdown causes heme/hemoglobin deficiency in zebrafish embryos; phenotype is rescued by MO-resistant *bdh2* mRNA while globin transcripts remain normal | *Danio rerio* embryos | Morpholino knockdown, RT-PCR confirmation of aberrant splicing, whole-mount o-dianisidine staining, isolated blood cell staining, mRNA rescue | Qualitative but replicated phenotype: marked reduction in o-dianisidine staining; second independent MO gave the same result; rescue restored normal staining; no reported reduction of *hbae1*/*hbae3* expression | Supports that zebrafish Bdh2 is required for heme biosynthesis/iron handling rather than globin gene transcription; consistent with a conserved siderophore-mediated mitochondrial iron delivery role rather than canonical ketone-body metabolism (pqac-00000000, pqac-00000010) | Devireddy et al., *Cell* (2010), DOI: 10.1016/j.cell.2010.04.040, URL: https://doi.org/10.1016/j.cell.2010.04.040 |
| Bdh2 enzymatic activity is NAD+-dependent oxidation of a dihydro-DHBA precursor to DHBA; DHBA binds 24p3 with high affinity | Recombinant mammalian BDH2 / 24p3 system | Enzyme assay with recombinant BDH2, catalytic Tyr mutant, NAD to NADH conversion assay, ligand-binding assays | 24p3 binding affinities reported at ~12 nM for 2,5-DHBA and ~8 nM for 2,3-DHBA; Tyr147/Phe mutation abolished activity | Strong biochemical evidence that BDH2 participates in endogenous catecholate siderophore production; links enzyme activity to iron trafficking via 24p3-bound DHBA, implying a cytosolic iron-chaperoning pathway connected to mitochondrial iron use (pqac-00000001) | Devireddy et al., *Cell* (2010), DOI: 10.1016/j.cell.2010.04.040, URL: https://doi.org/10.1016/j.cell.2010.04.040 |
| *bdh2* inactivation delays zebrafish erythroid maturation and causes hypohemoglobinization; rescue by *bdh2* mRNA and by 2,5-DHBA | *Danio rerio* erythrocytes/embryos | Morpholino knockdown, o-dianisidine staining, May-Grunwald/Giemsa morphology, N:C ratio quantification, mRNA rescue, 2,5-DHBA supplementation, iron dextran bypass tests | N:C ratio quantified on 300 cells (mean ± SD, *P* < 0.05); constitutive respiration ~3-fold lower and uncoupled respiration ~2.18-fold lower in morphants; o-dianisidine staining partially rescued by *bdh2* mRNA and by 2,5-DHBA; iron dextran failed to rescue mitochondrial iron deficiency | Indicates Bdh2 acts upstream of mitochondrial iron utilization in erythroid cells, with 2,5-DHBA as functional mediator; supports a pathway of siderophore-dependent mitochondrial iron import required for heme synthesis and erythroid maturation (pqac-00000005, pqac-00000006, pqac-00000011) | Davuluri et al., *PNAS* (2016), DOI: 10.1073/pnas.1600077113, URL: https://doi.org/10.1073/pnas.1600077113 |
| Loss of *bdh2* triggers premature mitophagy in zebrafish erythrocytes; blocking autophagy partially rescues maturation/hemoglobinization | *Danio rerio* erythrocytes | Confocal MitoTracker/LysoTracker imaging, electron microscopy, anti-OXPHOS staining, *atg7* morpholino coinjection, transcriptome/GSEA | Mitochondrial counts quantified on 50 cells (mean ± SD, *P* < 0.05); N:C ratio quantified on 300 cells (*P* < 0.05); suppression of *atg7* reduced mitochondrial clearance and partially rescued o-dianisidine staining/maturation | Places Bdh2 function at the intersection of mitochondrial iron metabolism and erythroid organelle clearance: siderophore depletion causes mitochondrial dysfunction, which drives premature mitophagy and delayed maturation (pqac-00000007, pqac-00000009) | Davuluri et al., *PNAS* (2016), DOI: 10.1073/pnas.1600077113, URL: https://doi.org/10.1073/pnas.1600077113 |
| BDH2 is dispensable for bulk ketone-body metabolism in vivo but required for endogenous siderophore/iron homeostasis; *bdh2*-null mice show anemia and splenic iron overload, partially rescued by 2,5-DHBA | Mouse (*bdh2* knockout) with cross-reference to zebrafish/yeast/cultured cells | Gene knockout, iron phenotyping, supplementation with 2,5-DHBA, comparative interpretation with prior zebrafish knockdown work | No numeric values in provided excerpt; reported outcomes include microcytic anemia, reduced serum iron, splenic iron overload, and partial rescue by 2,5-DHBA supplementation | Supports current view that BDH2’s primary conserved role is in siderophore-dependent intracellular iron trafficking and heme biology, not canonical cytosolic ketone oxidation; zebrafish phenotype is therefore mechanistically coherent with mammalian knockout data (pqac-00000002, pqac-00000003) | Liu et al., *Molecular and Cellular Biology* (2014), DOI: 10.1128/MCB.00231-14, URL: https://doi.org/10.1128/MCB.00231-14 |


*Table: This table compiles the strongest primary evidence supporting functional annotation of zebrafish bdh2/BDH2 (UniProt Q561X9), integrating zebrafish phenotypes with biochemical and mammalian ortholog data. It is useful for distinguishing the best-supported role in siderophore-dependent iron/heme metabolism from weaker ketone-metabolism annotations.*