|Validation across genders and environmental conditions of the set of five groups of probes belonging to the heat shock protein family to predict variability in tenderness|
|Initial tenderness||Overall tenderness|
|Predictors of tenderness||Number of animals||R2||P value||R2||P value|
|Expression levels of HspB1(Hsp27), DNAJA1, HspH1, HspA8||76||0.20||0.008||0.20||0.008|
|Intramuscular fat content, mean fiber area, total collagen content and collagen solubility||76||0.06||0.39||0.05||0.49|
|Intramuscular fat content, mean fiber area, total collagen content and collagen solubility plus expression levels of HspB1(Hsp27), DNAJA1, HspH1, HspA8||76||0.27||0.01||0.25||0.02|
Multiple regression analyses were performed with the combination of the 5 groups of probes (Hsp27, DNAJA1, HspH1, HspA8, plus two groups of probes for HspB1-Hsp27) to predict beef initial or overall tenderness for young bulls slaughtered year 1 (the reference group) or year 2 or steers slaughtered year 2. The four muscle biochemical traits (Intramuscular fat content, mean fiber area, total collagen content and collagen solubility) previously shown to be associated with beef quality  were analysed with a similar approach alone or in association with the 5 groups of probes (DNAJA1, HspH1, HspA8, plus two groups of probes for HspB1-Hsp27). The pooled relationship between muscle characteristics and gene expression with beef tenderness was calculated across animal groups after removing the gender and the year effects, i.e. by working on the deviation of each observation to the animal group muscle mean divided by the standard deviation for the group. The proportion of the variability in tenderness which is explained in the different situations is indicated (R2).
Hocquette et al.
Hocquette et al. BMC Veterinary Research 2012 8:135 doi:10.1186/1746-6148-8-135