Fig. 2

Correlation matrices between the gene expression of the 22 differential genes and the phenotypic traits of the ducklings. The correlation matrices were plotted for the R group (n = 18), the C group (n = 17), and the males (n = 19) and the female ducklings (n = 16) separately. The phenotypic traits are body weight, liver weight, percentages of liver lipids (Lipid) and liver dry mater (DM), plasma activities of ALP, ALT and AST and plasma concentrations of triglycerides (Triglycerid) and free fatty acids (FFA). The color scale indicates the strength of the correlation; blue for a positive correlation and red for a negative one. Only the significant correlations (with a P-value < 0.05) were plotted. For the genes, the imputed but not qqnorm transformed, normalized relative expressions were used and for the phenotypic data the raw values were used