Quantitative PCR analysis of xylanase and xyr1 gene expression by the strains overexpressing gene 77513 and by the strain with gene 77513 deleted. pMH15 is harboring the expression cassette as a double-copy and pMH15(S) as a single-copy. Panels A, B, C and D show the expression levels of xyn1, xyn2, xyn3 and xyr1 genes, respectively. The expression levels are shown as normalized against the signal of sar1. RNA extracted after 3 days (blue bars) and 5 days (red bars) of cultivation was used as a template. The values are means of three biological replicates. Error bars show the standard error of the mean.