Candidate Gene SNP Associations With Fat‐Free Mass (FFM) Measurements in Horses‐In‐Training. (June 2014) - Katz, L
Abstract : Introduction: Body composition including percentage of fat, fat mass and fat‐free mass (FFM) is an important consideration for athletes. An evaluation of FFM in racehorses concluded that racing performance is positively correlated with FFM both pre‐ and post‐training. Athletic performance is influenced by interactions among the environment and genes that influence anatomical, metabolic and physiological traits relevant to exercise. The aim of this study was to determine the effects of genetic variation in six candidate genes with functions in growth and metabolism ( IL1RA, PTPN1, MC3R, IGF1, LEPR and MSTN ) on FFM in Thoroughbreds. Methods: FFM was calculated from rump fat thickness measured ultrasonographically in 110 two‐year‐old Thoroughbred horses‐in‐training in the same yard after two (T2) and eight (T8) months of training. Twenty‐one SNPs in six genes were selected from the EquCab2.0 SNP database and were genotyped for all horses using custom Sequenom SNP genotyping assays. Quantitative tests of association were performed between SNPs and FFM at T2 and T8, and the FFM ratio between the two time points (T2 : T8) using PLINK software. Results: Two SNPs in both the IGF1 (Insulin‐Like Growth Factor 1) and PTPN1 (Protein Tyrosine Phosphatase, Non‐Receptor Type 1) genes were significantly associated with FFM (T2) (P<0.05). The two IGF1 SNPs and two LEPR (Leptin Receptor) gene SNPs were significantly associated with FFM (T8) (P<0.05). One LEPR SNP was significantly (P<0.005) associated with changes in FFM (T2 : T8). Conclusions: These results suggest a genetic contribution to FFM variation in Thoroughbreds. Further validation will determine whether these SNPs may be used to predict the effects of training on FFM. Ethical Animal Research: Institutional Animal Research Ethics Committee approval was obtained. Explicit owner informed consent for participation in this study is not stated.Sources of funding: The study was funded by a Science Foundation Ireland, President of Ireland Young Researcher Award (04‐YI1‐ B539).Competing interests: Dr Hill is a co‐founder and Chairman of Equinome Ltd.