Figure 2.

Total protein, collagens and MMPs. Changes in (a) total protein content, (b) total content of collagens estimated based on 4-hydroxyproline released upon acidic hydrolysis of larval total proteins, and (c) activity of general metalloproteinases (MMPs, collagenases). All analyses were performed on extracts of whole body larvae of different variants (diapause maintenance: SD3, SD6, SD1 (red columns); cold acclimation: SDA (blue column); see Table 1)) and each column is a mean of 3 biological replicates. Means were compared using one-way ANOVAs followed by Bonnferoni’s multiple comparison tests (different letters indicate significantly different means). Note that nanomolar amounts of hydroxyproline were released from collagens upon acidic hydrolysis (c), while the total pool of free hydroxyproline in larval tissues is three orders lower—approximately 4–8 femtomoles [22].