Cytochrome P450 1 Genes in Birds: Evolutionary Relationships and Transcription Profiles in Chicken and Japanese Quail Embryos
2011 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 6, no 12, e28257Article in journal (Refereed) Published
Background: Cytochrome P450 1 (CYP1) genes are biomarkers for aryl hydrocarbon receptor (AHR) agonists and may beinvolved in some of their toxic effects. CYP1s other than the CYP1As are poorly studied in birds. Here we characterize avianCYP1B and CYP1C genes and the expression of the identified CYP1 genes and AHR1, comparing basal and induced levels inchicken and quail embryos.
Methodology/Principal Findings: We cloned cDNAs of chicken CYP1C1 and quail CYP1B1 and AHR1. CYP1Cs occur in severalbird genomes, but we found no CYP1C gene in quail. The CYP1C genomic region is highly conserved among vertebrates.This region also shares some synteny with the CYP1B region, consistent with CYP1B and CYP1C genes deriving fromduplication of a common ancestor gene. Real-time RT-PCR analyses revealed similar tissue distribution patterns for CYP1A4,CYP1A5, CYP1B1, and AHR1 mRNA in chicken and quail embryos, with the highest basal expression of the CYP1As in liver,and of CYP1B1 in eye, brain, and heart. Chicken CYP1C1 mRNA levels were appreciable in eye and heart but relatively low inother organs. Basal transcript levels of the CYP1As were higher in quail than in chicken, while CYP1B1 levels were similar inthe two species. 3,39,4,5,59-Pentachlorobiphenyl induced all CYP1s in chicken; in quail a 1000-fold higher dose induced theCYP1As, but not CYP1B1.
Conclusions/Significance: The apparent absence of CYP1C1 in quail, and weak expression and induction of CYP1C1 inchicken suggest that CYP1Cs have diminishing roles in tetrapods; similar tissue expression suggests that such roles may bemet by CYP1B1. Tissue distribution of CYP1B and CYP1C transcripts in birds resembles that previously found in zebrafish,suggesting that these genes serve similar functions in diverse vertebrates. Determining CYP1 catalytic functions in differentspecies should indicate the evolving roles of these duplicated genes in physiological and toxicological processes.
Place, publisher, year, edition, pages
2011. Vol. 6, no 12, e28257
Biochemistry and Molecular Biology Developmental Biology Evolutionary Biology
IdentifiersURN: urn:nbn:se:uu:diva-165745DOI: 10.1371/journal.pone.0028257ISI: 000298171400056OAI: oai:DiVA.org:uu-165745DiVA: diva2:474610