title: Age-dependent expression of osteochondrosis-related genes in equine leukocytes.
abstract: BACKGROUND
  Osteochondrosis (OC) is a developmental disease in horses which has a significant impact on the horse's welfare and performance. The early disturbance in the process of endochondral ossification progresses to inflammatory and repair processes in older horses. Previously, differentially expressed genes in leukocytes of OC-affected horses have been identified. The aim of the present study is to detect age-related changes in these differentially expressed genes.
  
  
  METHODS
  The expression of OC-related genes was analysed by real-time PCR and subsequent statistical analysis (ΔΔCT) in the leukocytes of 135 Belgian Warmblood horses divided into three different age groups: <12 months (n=47), 18-24 months (n=50) >30 months (n=38).
  
  
  RESULTS
  Relative expression of genes of horses less than 12 months of age showed significant induction of the genes MGAT4A, PRKCG, MHCI, ApoB, ApoB3G, B4GALT6 and a significantly lower expression of the genes OAS3. Horses of 18-24 months of age, showed a significantly higher expression of the genes TBC1D9, MGAT4A, IFIH1, MHCIIa and MMP1. Horses of more than 30 months of age showed a significantly higher expression of the genes MGAT4A, HP, SECTM1 compared with their age-matched control groups.
  
  
  CONCLUSIONS
  The study demonstrates that OC-related genes are differentially expressed in horses of different ages compared with their age-matched controls. Some of the genes may be implicated in cell signalling and differentiation as well as carbohydrate and lipid metabolism and inflammation. However, the causal relationship between the differentially expressed genes and the development and progression of the OC lesions needs to be determined.
authors.affiliation: University of Liège , Liège , Belgium ; Equine Research and Development Center , Mont-le-Soie , Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Mendoza
authors.affiliation: Computational Biology Institute (IBC) , France ; University of Montpellier2 , Montpellier , France ; Acobiom , Montpellier , France.
authors.forename: D
authors.initials: D
authors.lastname: Piquemal
authors.affiliation: Equine Research and Development Center , Mont-le-Soie , Belgium.
authors.forename: J P
authors.initials: JP
authors.lastname: Lejeune
authors.affiliation: Equine Research and Development Center , Mont-le-Soie , Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Vander Heyden
authors.affiliation: Acobiom , Montpellier , France.
authors.forename: F
authors.initials: F
authors.lastname: Noguier
authors.affiliation: Acobiom , Montpellier , France.
authors.forename: R
authors.initials: R
authors.lastname: Bruno
authors.affiliation: University of Liège , Liège , Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Sandersen
authors.affiliation: University of Liège , Liège , Belgium ; Equine Research and Development Center , Mont-le-Soie , Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Serteyn
keywords: Horses; Joint diseases; Lameness; Orthopaedics; Skeletal development