RNA-Seq analysis implicates detoxification pathways in ovine mycotoxin resistance

PLoS One. 2014 Jun 17;9(6):e99975. doi: 10.1371/journal.pone.0099975. eCollection 2014.

Abstract

Mycotoxin induced hepatoxocity has been linked to oxidative stress, resulting from either an increase in levels of reactive oxygen species (ROS) above normal levels and/or the suppression of antioxidant protective pathways. However, few detailed molecular studies of mycotoxicoses in animals have been carried out. This study use current RNA-seq based approaches to investigate the effects of mycotoxin exposure in a ruminant model. Having first assembled a de novo reference transcriptome, we use RNA-Seq technology to define in vivo hepatic gene expression changes resulting from mycotoxin exposure in relationship to pathological effect. As expected, characteristic oxidative stress related gene expression is markedly different in animals exhibiting poorer outcomes. However, expression of multiple genes critical for detoxification, particularly members of the cytochrome P450 gene family, was significantly higher in animals exhibiting mycotoxin tolerance ('resistance'). Further, we present novel evidence for the amplification of Wnt signalling pathway activity in 'resistant' animals, resulting from the marked suppression of multiple key Wnt inhibitor genes. Notably, 'resistance' may be determined primarily by the ability of an individual to detoxify secondary metabolites generated by the metabolism of mycotoxins and the potentiation of Wnt signalling may be pivotal to achieving a favourable outcome upon challenge.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Resistance
  • Gene Ontology
  • Inactivation, Metabolic
  • Liver / drug effects
  • Liver / metabolism
  • Mycotoxicosis / genetics
  • Mycotoxicosis / metabolism
  • Mycotoxicosis / veterinary*
  • Mycotoxins / metabolism
  • Mycotoxins / toxicity*
  • Sequence Analysis, RNA
  • Sheep
  • Sheep Diseases / genetics
  • Sheep Diseases / metabolism*
  • Sheep, Domestic
  • Transcriptome
  • Wnt Signaling Pathway

Substances

  • Mycotoxins

Associated data

  • SRA/SRA102080
  • SRA/SRP030219
  • SRA/SRX359140
  • SRA/SRX359141
  • SRA/SRX359259
  • SRA/SRX359297
  • SRA/SRX359298
  • SRA/SRX359299
  • SRA/SRX359300
  • SRA/SRX359301

Grants and funding

This work was supported in part by the Epigenomics Based Prognostics Program (AS is the PI) and the High Efficiency Sensor Program (AS is a co-PI) both funded by the Ministry of Business, Industry and Employment (MBIE) of the New Zealand Government. JZ acknowledges scholarship support from the China Scholarship Council. The authors would like to further acknowledge the support of the Developmental Epigenetics Lab, Liggins institute, University of Auckland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.