Ask about this productRelated genes to: BCO2 Blocking Peptide
- Gene:
- BCO2 NIH gene
- Name:
- beta-carotene oxygenase 2
- Previous symbol:
- BCDO2
- Synonyms:
- FLJ34464, B-DIOX-II
- Chromosome:
- 11q23.1
- Locus Type:
- gene with protein product
- Date approved:
- 2002-04-10
- Date modifiied:
- 2014-11-19
Related products to: BCO2 Blocking Peptide
Related articles to: BCO2 Blocking Peptide
- The yellow body coloration of large yellow croaker (Larimichthys crocea) constitutes a crucial economic trait, yet its underlying genetic regulatory mechanisms remain poorly understood. This study systematically elucidated the molecular basis of body color variation by integrating genome resequencing and skin transcriptome analyses, combined with the contextual analysis of key pigmentation-related genes and phenotypic histological validation. 200 phenotyped individuals (including yellow-selected lines, F1 progeny, and normal control groups, all derived from a well-characterized aquaculture stock) identified 39 significantly associated SNPs (-log₁₀(P) ≥ 6), mapping to multiple candidate genes. These genes were significantly enriched in pathways related to pigment deposition (GO:0033059), melanosome organization (GO:0032438), melanogenesis, and tyrosine metabolism. Cross-developmental stage transcriptome analysis revealed 2395 differentially expressed genes (DEGs). Multi-omics integration identified eight overlapping candidate genes, including tyrp1, slc45a2, oca2, and dgat2, among which tyrp1 was prioritized for in-depth validation based on its core regulatory role in eumelanin synthesis, significant SNP association signal, and consistent downregulation in transcriptomic data. Experimental validation demonstrated that the g.895C > T mutation in exon 2 of tyrp1b was strongly significantly associated with the yellow phenotype: the frequency of mutant genotypes (TT/CT) reached 92.86%in the yellow-selected group, whereas the control group exclusively exhibited the wild-type genotype (CC). qPCR confirmed significantly downregulated tyrp1b expression in the skin of yellow individuals, consistent with the transcriptome trend. Histological and stereomicroscopic observations of skin tissues further validated the physiological basis of the yellow phenotype, revealing a significant reduction in melanophore number and abnormal melanosome morphology in yellow-phenotype individuals, accompanied by increased xanthophore density. These results suggest that tyrp1b mutation is strongly associated with the yellow phenotype. However, the presence of a wild-type CC individual in the yellow group indicates that this mutation is not strictly required for yellow coloration, suggesting that other genetic or environmental factors may also contribute to the phenotype, Additionally, downregulation of the carotenoid metabolism gene bco2 coupled with upregulation of xdh, together with the functional changes of slc45a2 and oca2, may synergistically promote xanthophore pigment deposition, contributing to the yellow phenotype. As melanin synthesis in large yellow croaker relies on the conserved tyrosinase pathway and transporter proteins, mutations in associated genes (tyrp1b, slc45a2, oca2) represent a primary underlying cause for the loss of melanin-based coloration and transition to a yellow phenotype in L. crocea. These findings provide key molecular targets and a theoretical foundation for molecular breeding of body color in this species, and also enrich the understanding of xanthism regulatory mechanisms in teleosts. - Source: PubMed
Publication date: 2026/06/15
Jiang LihuaChen ShunLi WeiyeXu KaidaShi FumingLi TianyuYin XiaolongZheng JialangLiu LifanSong WeihuaYan Xiaojun - Vitamin A is an essential micronutrient that supports vision, immunity, and development, yet excess vitamin A can be toxic. Most vertebrates maintain tightly regulated vitamin A levels by cleaving dietary carotenoids into retinoids via specialized enzymes, including the carotenoid oxygenase Bco2. To what extent genetic changes in carotenoid-metabolism enzymes such as Bco2 drive natural variation in vitamin A homeostasis remains unclear. Here, we show that some cave-adapted populations of the Mexican tetra (Astyanax mexicanus) have evolved loss-of-function mutations in bco2a. The mutations yield enzymatically inactive Bco2a proteins and are associated with dramatic carotenoid and vitamin A accumulation. The bco2a locus shows signatures of selection in these cavefish populations, suggesting that loss of Bco2a function could be advantageous under certain cave conditions. Contrary to expectations from mammalian models in which Bco2 loss induces oxidative damage, cavefish appear to tolerate carotenoid accumulation and may benefit from elevated carotenoid stores in nutrient-variable caves. Our findings reveal that the vitamin A regulatory system is evolutionarily flexible and provide a framework for understanding how animals balance essential nutrient thresholds in extreme environments. VIDEO ABSTRACT. - Source: PubMed
Publication date: 2026/05/25
Guerra David PerézBandara SepalikaLeal FranciscaVasquez-Gross HansPetereit Julivon Lintig JohannesRiddle Misty R - The guinea fowl (), a thermo-tolerant and disease-resilient poultry species, holds great potential for sustainable poultry production in climate-vulnerable regions. The genomic aspects of this species remain largely understudied. The present study aims to delineate the patterns of domestication and understand the evolutionary dynamics of guinea fowl populations (wild and domestic) across three continents, utilizing whole-genome sequencing data from 122 genomes. The population structure analyses (ADMIXTURE, PCA, phylogeny, F, LD, and MAF) revealed that Indian guinea fowl (CARI) shared close ancestry with Iranian (IRAD) and Chinese (CHID) domesticated populations while remaining distinct from wild lineages. The runs of homozygosity (ROH) identified 49,088 segments, with short fragments (ROHs) preponderant in Indian and domestic populations, reflecting historical inbreeding and effects of domestication cum selection. Copy number variation (CNV) analysis revealed 105,178 CNVs concatenated into 40,067 CNV regions (CNVRs) across 11 populations, establishing the first CNV atlas for guinea fowl at the global level. Gene annotation of overlapping ROH and CNVRs revealed 1080 common candidates across Asian guinea fowl populations, i.e., the Indian guinea fowl (CARI), IRAD, and CHID, including , , , and . These genes have earlier been associated with immune regulation, stress response, and thermal adaptation. Selection signature scans, integrating intra-population (iHS) and inter-population (XP-EHH) approaches, uncovered genes under positive selection linked to immune response (like , , and ), thermo-tolerance (like and ), lipid metabolism (like and ), and pigmentation (). These signatures highlight the molecular basis of resilience in guinea fowl and their potential to withstand climate-induced stresses. This study presents the first global CNV atlas for guinea fowl and provides the first comprehensive genomic characterization of the Indian domestic population, integrating ROH, CNV, and selection signature analyses. It offers a comprehensive assessment of guinea fowl genomes (wild and domesticated) across three continents, offering insights into domestication, evolutionary dynamics, and the genetic basis of their adaptation and resilience. - Source: PubMed
Publication date: 2026/03/25
Tomar SimmiAhmad Sheikh FirdousGangwar MunishAzhaguraja ManoharanKush AlishaTrivedi AbhaGandham Ravi KumarTiwari Ashok Kumar - [This corrects the article DOI: 10.1002/bco2.70058.]. - Source: PubMed
Publication date: 2026/04/10
- β-carotene-15,15-dioxygenase (BCO1) and β-carotene-9,10-dioxygenase (BCO2) are essential enzymes that catalyze the oxidative cleavage of carotenoids, playing key roles in carotenoid homeostasis and pigmentation. In this study, HcBCO1 and HcBCO2 were identified from freshwater pearl mussel Hyriopsis cumingii to investigate their potential roles in carotenoid metabolism and shell nacre color formation. HcBCO1 consisted of a 1560 bp ORF, a 171 bp 5' UTR and a 171 bp 3' UTR, HcBCO2 consisted of a 1590 bp ORF, a 3 bp 5' UTR and a 394 bp 3' UTR. qRT-PCR revealed that HcBCO1 and HcBCO2 were expressed in all detected tissues, with the white shell strain showed significantly higher expression levels than purple and golden strains. By in situ hybridization, strong positive signals of HcBCO1 and HcBCO2 were detected in the outer fold (OF), middle fold (MF), inner fold (IF), and ventral mantle (VM). Further functional analysis showed that recombinant HcBCO1 and HcBCO2 expressed in E. coli were capable of cleaving β-carotene, with the pGEX-4 T-HcBCO1 group exhibiting a stronger cleavage ability. In addition, dsRNA interference demonstrated that suppressing HcBCO1/HcBCO2 expression increased carotenoid accumulation in the mantle. Our results indicate that both HcBCO1 and HcBCO2 are capable of cleaving carotenoids, with HcBCO1 exhibiting superior activity. This study offers new insights into shell color diversity in bivalves and provides potential molecular markers for genetic improvement of color and optimization of pearl hue through carotenoid metabolism regulation. - Source: PubMed
Publication date: 2026/03/14
Wang ZhiyanYan LingLiu ChuntongLu TingtingZhang MinZhang YaoChen YangBai Zhiyi