Genomic region with a linear time effect. Fitted linear time effect for the genomic region of gene AT1G62500 on the forward strand of chromosome 1. The different replicates are indicated by ∘, + and , while the different days are represented by different colors: black (D8), red (D9), green (D10), blue (D11), cyan (D12) and magenta (D13). The grey rectangles indicate the detected regions showing a significant linear time effect, while the black line corresponds with the coefficient function of the linear effect. The negative sign of the coefficients implies a decreasing effect over time. More specifically, the effect at probe t is .