Expression pattern of IL-16.A, tissue distribution of IL-16. RNA samples were extracted from healthy Eriocheir sinensis, and EsIL-16 expression was analyzed by quantitative RT-PCR with β-actin as the internal reference. Total RNA was extracted from seven different tissues of crab. Each sample was taken from at least three crabs; data shown are the means ± SD. Three independent repeats were performed (≥5 crabs per sample), with different lowercase letters indicating the significance (one-way ANOVA). B–E, mRNA expression of EsIL-16 in hemocytes as assessed by quantitative RT-PCR over a time course after Staphylococcus aureus (B) or Vibrio parahaemolyticus (C) stimulation in vitro and S. aureus (D) or V. parahaemolyticus (E) infection in vivo. RNA was extracted at 0, 4, 8, 12, 24, 36, and 48 h after bacterial challenge. Bars represent the mean ± SD from three independent samples, with at least five crabs per sample. ∗p < 0.05, ∗∗p < 0.01 (Student's t test). IL-16, interleukin 16.