Statistical analysis of microarray targets. Characteristics of genes (represented by Pinus taeda ESTs) showing preferential amplification by one method or the other. From the results of the microarray normalization, the genes were divided into two groups, those showing higher expression for PCR amplified transcripts (S') and those showing higher expression for T7 amplified transcripts (M'). (A) Distribution of expression for all the genes (2190 ESTs) in the S' and M' groups. (B) Transcript abundance of all the genes and selected genes (represented by 309 ESTs) in the S' and M' group. (C) Transcript lengths for the two groups, estimated by finding the Arabidopsis thaliana homologs either from the nucleotide sequence (BLASTn™) or the amino acid sequence (BLASTx™) of the Pinus taeda contigs. The variance of the transcript length is significantly smaller for the S' group than for the M' group for both the nucleotide and protein estimates. There is furthermore a significantly greater mean length for the M' group than for the S' group. (D) GC content sequenced ends of the selected genes of the S' and M' groups. The S' group is significantly more GC rich than the M' group, for both ESTs and contigs. Bars indicate the range; boxes extend from the 25th to the 75th percentile, with a horizontal line at the median.