Fig. 3. (A) Western blot profiles obtained for the detection of HSP70 proteins in P. grasslei using the anti-rat polyclonal antibody (lane 1) or the anti-chicken monoclonal antibody (lane 2). Several bands with a molecular mass between 70 and 75 kDa were detected for both antibodies. A weak band around 150 kDa was also observed with the polyclonal antibody. (B) Dot blot detection of HSP70 proteins in P. grasslei using the anti-rat polyclonal HSP70 antibody. Each band corresponds to a different individual. The first two columns represent reference (R) and heat-shocked (HS) individuals frozen immediately after the shock (Expts 4a and 4b; 0 h). The two central columns show R and HS specimens that were maintained for 1.5 h at 15°C after the shock (Expts 5a and 5b, 1.5 h). Finally, the two last columns show R and HS animals maintained for 3.5 h at 15°C after the heat shock (Expts 6a and 6b, 3.5 h). (C) Dot blot signal intensity comparison of HSP70 levels for R (grey columns) and HS (black columns) P. grasslei. The density of each band (expressed in arbitrary units, a.u.) was calculated using a plug-in based on ImageJ software. Each column represents the mean of the band density (±s.d.) for the eight R or HS individuals from the corresponding column above (except for Expt 6a where only seven P. grasslei were used; the dash shows the empty well). The asterisk indicates a significant difference between treatments (Mann–Whitney test; U=7, P=0.007).