Figure 1. Heat shock effects on neutrophil recruitment.

(A) Schematic illustration of the experimental setup for otic vesicle infection shown in C. (B) Schematic illustration of the experimental setup for tail fin wounding shown in E. The red rectangle indicates heat shock at 38-39°C for 1 hour. Grey circles indicate the time point for neutrophil counting. (C) Quantification of neutrophils at the otic vesicle (yellow dotted line) in control (cntl) and heat shocked (HS) larvae at 2 hours post infection (2 hpi). Larvae were injected with 100 CFU of Streptococcus iniae (S.i) into the otic vesicle (ear) at 3 days post fertilization (dpf). HS larvae showed decreased neutrophil recruitment compared with controls. **P<0.01 (two-tailed, unpaired t-test). (Right panel) Representative images of Sudan Black-stained larvae. Lateral view of the head of larvae at 2 hpi. (D) Survival of control (cntl) and heat shocked (HS) larvae infected with S.i. in the ear over time. Control and HS larvae showed a similar survival rate. dpi; days post infection. (E) Quantification of neutrophils at wounds in control (cntl) and heat shocked (HS) larvae at 1 and 4 hour post wounding (hpw). HS larvae showed fewer neutrophils at wounds at 4 hpw compared with controls. ****P<0.0001; ns, not significant (two-tailed, unpaired t-test). (Right panel) Representative images of Sudan Black-stained larvae. Lateral view of the tail fin of larvae at 3 dpf. (F) Quantification of neutrophils in whole larvae for control (cntl), heat shocked (HS) and 3 hours post heat shocked (3 hpHS) larvae. (Right panel) Representative images of Sudan Black-stained larvae. Data are representative of at least three experiments.