Expression of ap-GnRH in different A. californica tissues examined by RT-PCR (top panel). ap-actin was used as a control to ensure the quality of RNA samples (bottom panel). No RT negative controls used RNA samples that have not been reverse transcribed (middle panel). PCR products were stained with ethidium bromide. The sizes of the PCR products are shown on the right. CNS, central nervous system; OVT, ovotestis; Ceb, cerebral ganglia; P/P, pedal/pleural ganglia; AtG, atrial gland; AbG, abdominal ganglia; -Cont, negative water control.