Representative phosphoproteome gels of P. vexillosa. Pre: pre-competent larvae, Com: competent larvae, Juv: newly metamorphosed juveniles. (A) The protein extracts were separated on narrow-range IPG strips (pH/pI 4-7) followed by 12.5% 2-DE and stained with the phosphoprotein-specific stain ProQ Diamond. (B) Number of phosphoprotein spots reproducibly detected in the three developmental stages. (C) Number of up-regulated and down-regulated phosphoprotein spots (Student's t-test (p < 0.01, n = 3).