RT-PCR profiling of H. americanus calcitonin-like diuretic hormone (Homam-CLDH) transcript in neural, midgut and cardiac tissues of the lobster. Using the gene-specific primer set shown in Fig. 1, RT-PCR tissue profiling was conducted to assess the distribution of the lobster CLDH-encoding message. A robust band of the predicted size of the CLDH PCR product (496 bp in length; base pair ladder shown in lane 1 of the left gel) was consistently detected in brain (lane 3 of the left gel), eyestalk ganglia [including in the X-organ (XO); lanes 4 and 5 of the left gel, respectively], cardiac ganglia (CG; lane 1 of the right gel) and commissural ganglia (CoG; lane 2 of the right gel). In contrast, no product was detected in the midgut proper or heart muscle (lanes 4 and 5 of the right gel, respectively). Three faint bands (Fig. 2) were detected in posterior midgut caecum (PMC; lane 3 of the right gel); however, none corresponded to the size of the predicted 496 bp product. No product was detected in the negative control (Neg. control; lane 1 of the right gel).