Fig. 4: A follicle-like structure in S. clava larva functions in TH synthesis and storage.

a The follicle-like structure, at the most anterior of S. clava larval trunk, is labeled by antibodies of ScTG-like protein (magenta), phalloidin (green), and DAPI (blue). Scale bars = 10 μm. The experiment was independently repeated three times with similar results. b Diagram of the follicle-like structure at the central arterial of S. clava larval trunk. c The follicle-like structure is labeled by the antibody of TPO protein (magenta), phalloidin (green), and DAPI (blue). Scale bars = 10 μm. The experiment was independently repeated three times with similar results. d The abolishment of TH synthesis inside of the follicle-like structure after knocking down of ScTg-like gene. Two specific siRNAs, siRNA-1 and siRNA-2, was used to knock down the expression of ScTg-like gene, respectively. Negative control, larvae treated with NC siRNAs (NC). Blank control, larvae treated with FSW. The concentrations of siRNAs are 0.4 μM. The presence of T3 signals in the follicle-like structures was detected using antibody of T3 (magenta). The phenotypes of the follicle-like structures were labeled by phalloidin (green) staining. The nuclei are labeled using DAPI (blue). The fraction showed on each image indicates the number of S. clava with the phenotypes showed in the image / total number of S. clava in each experimental group. Scale bars = 5 μm.