Figure 3.

Dynamic profiles of mRNA expression and enzyme activities of individual peptidases during the feeding of Ixodes ricinus females. For each time point, the guts were dissected from 15-20 females removed from four guinea pigs. Half of the guts were processed either for total RNA isolation or gut tissue extraction as described above. Gene expression profiles of the indicated enzymes were determined by qRT-PCR, using elongation factor 1 as a reference gene. The expressions were related to the maximum mRNA level set as 100%. Columns correspond to the average value of triplicate technical determinations, while error bars indicate the corresponding standard deviations. The enzyme activity curves of indicated peptidases were determined using specific fluorogenic substrates and shielding inhibitors to mask possible interference from other peptidases (see Table 1). Enzymatic activities in the homogenates were normalized per one gut tissue. The circles display the average activities obtained from triplicate measurements. The standard deviations were ≤5% of the average value and are not shown.