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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #172226
Title: EVALUATION OF CANDIDATE GENE EFFECTS FOR BEEF BACKFAT VIA BAYESIAN MODEL SELECTIONJ

Author
item WU, X - WASH STATE UNIVERSITY PUL
item Macneil, Michael
item DE, S - WASH STATE UNIVERSITY PUL
item XIAO, Q - WASH STATE UNIVERSITY PUL
item MICHAL, J - WASH STATE UNIVERSITY PUL
item GASKINS, C - WASH STATE UNIVERSITY PUL
item REEVES, J - WASH STATE UNIVERSITY PUL
item BUSBOOM, J - WASH STATE UNIVERSITY PUL
item WRIGHT JR, R - WASH STATE UNIVERSITY PUL
item JIANG, Z - WASH STATE UNIVERSITY PUL

Submitted to: Genetica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2005
Publication Date: 9/15/2005
Citation: Wu, X.L., Macneil, M.D., De, S., Xiao, Q.J., Michal, J.J., Gaskins, C.T., Reeves, J.J., Busboom, J.R., Wright Jr, R.W., Jiang, Z. 2005. Evaluation of candidate gene effects for beef backfat via bayesian model selectionj. Genetica 125L103-113.

Interpretive Summary: A candidate gene is one with biological actions involved in the development or physiology of the trait of interest (functional candidate gene) or chosen from the neighborhood of previous identified QTLs (positional candidate gene). Polymorphisms within selected candidate genes can be tested for association with variation in the quantitative trait so as to better understand their effects. Genes encoding Diacyglycerol O-acyltranferase 1, thyroglobulin, leptin, growth hormone 1 and fatty acid binding protein (heart) like 6 have been proposed as affecting subcutaneous fat thickness in beef cattle. However, relative magnitude of effects and thus importance of each of these genes in controlling phenotypic variation remains unknown. The objectives of this research were to 1) implement Bayesian model selection procedures for studying candidate gene effects using SAS® and 2) evaluate the effects of five previously identified candidate genes on subcutaneous fat thickness in a Wagyu x Limousin test population. Polymorphisms in all five candidate genes were significantly associated with variation in fat thickness. Effects of the Diacyglycerol O-acyltranferase gene were found to be relatively important in affecting subcutaneous fat thickness in a F2 WagyuLimousin population of beef cattle.

Technical Abstract: Candidate gene approaches provide a tool for exploring and localizing causative genes affecting quantitative traits and the underlying variation may be better understood by determining the relative magnitudes of effects of their polymorphic. Diacyglycerol O-acyltranferase 1 (DGATI), thyroglobulin (TG), leptin (LEP), growth hormone 1 (GH1) and fatty acid binding protein (heart) like 6 (FABP3) have been previously identified as genes contributing to genetic control of subcutaneous fat thickness (SFT) in beef cattle. In the present research, Bayesian model selection was used to evaluate effects of the five candidate genes by comparing competing non-nested models and treating candidate gene effects as either random or fixed. The analyses were implemented in SAS® to simplify the programming and computation. Phenotypic data were from a F2 population of Wagyu x Limousin cattle. The five candidate genes had significant but varied effects on SFT in this population. Bayesian model selection identified the DGAT 1 (diacyglycerol O-acyltranferase 1) model as the one with the greatest model probability, whether candidate gene effects were considered random or fixed and DGAT 1 had the greatest additive effect on SFT.