Component
BCO2 loss
Bco2-knockout state in the cited mice.
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
Where it participates (unsigned role)
Bco2-null mice accumulated more hepatic beta-cryptoxanthin than wild-type and Bco1-null mice after repeated injections.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_location
- Figure 10B
- experimental_model
- Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids.
- exposure
- Twelve-week-old females; pharmacological beta-cryptoxanthin injections on three consecutive days; n=3/genotype.
- limitations
- Injection bypasses intestinal absorption; not nutritional deficiency.
- nutrient_topic
- Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
- organism
- Mus musculus
- outcome
- Bco2-null mice accumulated more hepatic beta-cryptoxanthin than wild-type and Bco1-null mice after repeated injections.
- plain_language
- Removing BCO2 impaired clearance of this carotenoid.
- primary_references
- [va-amengual-2013] Two Carotenoid Oxygenases Contribute to Mammalian Provitamin A Metabolism (2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3837149/ DOI: 10.1074/jbc.M113.501049
- tissue_or_cell_type
- Liver
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 246–258
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids. · source_derived_draft · unverified_draft
### va-bco2-loss-cryptoxanthin Bco2-null mice accumulated more hepatic beta-cryptoxanthin than wild-type and Bco1-null mice after repeated injections. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Removing BCO2 impaired clearance of this carotenoid. organism: Mus musculus tissue_or_cell_type: Liver experimental_model: Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids. limitations: Injection bypasses intestinal absorption; not nutritional deficiency. exposure: Twelve-week-old females; pharmacological beta-cryptoxanthin injections on three consecutive days; n=3/genotype. outcome: Bco2-null mice accumulated more hepatic beta-cryptoxanthin than wild-type and Bco1-null mice after repeated injections. evidence_location: Figure 10B [va-amengual-2013] Two Carotenoid Oxygenases Contribute to Mammalian Provitamin A Metabolism (2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3837149/ DOI: 10.1074/jbc.M113.501049
Complete structured claim and evidenceIsx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- Retinoid/ISX control of a shared intestinal transporter affects vitamin E status.
- evidence_location
- Figure 7
- experimental_model
- Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets.
- exposure
- Females; ten weeks of AIN93G with 75 IU vitamin E/kg, with or without 50 mg zeaxanthin/kg.
- limitations
- Accumulation is not a clinical benefit; compound mutants had a larger effect than Isx single mutants.
- nutrient_topic
- Vitamin A research collection; topical membership is not evidence of a direct dietary effect. · Vitamin A
- organism
- Mus musculus
- outcome
- Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels.
- plain_language
- Disrupting vitamin A feedback also changed vitamin E accumulation.
- primary_references
- [va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072
- tissue_or_cell_type
- Jejunum and liver
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin A: forms, mechanisms, deficiency and excess (2026-09-17) · lines 302–315
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. · source_derived_draft · unverified_draft
### va-isx-loss-tocopherol Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels. Condition category: machinery_impairment nutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect. plain_language: Disrupting vitamin A feedback also changed vitamin E accumulation. organism: Mus musculus tissue_or_cell_type: Jejunum and liver experimental_model: Isx, Bco1, Bco2 and Scarb1 mouse mutants; promoter binding and controlled diets. limitations: Accumulation is not a clinical benefit; compound mutants had a larger effect than Isx single mutants. exposure: Females; ten weeks of AIN93G with 75 IU vitamin E/kg, with or without 50 mg zeaxanthin/kg. outcome: Isx-deficient mice had higher hepatic alpha-tocopherol; the Isx/Bco2 double mutant showed about twice wild-type levels. evidence_location: Figure 7 cross_nutrient: Retinoid/ISX control of a shared intestinal transporter affects vitamin E status. [va-widjajaadhi-2015] A genetic dissection of intestinal fat-soluble vitamin and carotenoid absorption (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4424956/ DOI: 10.1093/hmg/ddv072
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.