Identifying potential biomarkers to improve production in pigs

Work Package 5 of the Prohealth consortium aims to identify molecular markers that are associated with poor production in pigs. Microarrays are a powerful tool which will enable us to determine which genes in the affected tissues are up- or down-regulated as a result of the farm environmental condition. The application of software analysis packages such as GeneSpring will allow us to locate and pinpoint these genes to particular physiological or immunological pathways and help us to identify genes or sets of genes which have predictive value in identifying animals which are at risk.

As part of an EU wide consortium, Prohealth has access to samples from a variety of countries including Belgium, Spain, France and the Republic of Ireland. Agilent 4x44K microarrays will be used to analyse the changes in gene expression from animals reared in different commercial and experimental farms. This work focuses on data obtained from an experimental design performed at INRA (France) on Large-White pigs housed in poor or high hygiene conditions and exhibiting clear differences in growth performance and plasma immune status according to housing conditions. RNA from tissue samples preserved in RNAlater have been extracted, labelled and hybridised on the arrays at the University of Nottingham (UK). The arrays were analysed with a GenePix 4000B microarray scanner. Ingenuity Pathway Analysis will be used to recognise specific gene pathways and identify potential biomarkers for certain diseases and environmental conditions.

Initial results from the microarrays have been compared with results obtained using a Biomark high-throughput RT-PCR device (Fluidigm) at INRA. Preliminary data indicates that the two methods show similar results. Initially, only the immune-related genes were analysed by microarray, since prior to microarray analysis, the Biomark analysis was used to assess expression of 90 immune-related genes in three different tissues from pigs bred in poor or high hygiene conditions. The array results indicated that over 30 immune-related genes were over-expressed in pigs reared on a high hygiene farm compared to a poor one.

Our initial results are promising and are comparable with other molecular methods such as the Biomark system. Many more genes other than the immune-related ones are expected to have differences in expression between pigs bred in two extreme hygiene conditions. Identifying the molecular pathways and the individual genes which are differentially expressed will allow us to define a set of biomarkers specific to particular diseases or environmental conditions. This work was conducted under the EU-funded PROHEALTH project.

Disclosure of Interest: None Declared.