The gut of newly transformed schistosomula is active and likely facilitates RNAi.

After their preparation from cercariae, schistosomula were incubated with (A) 30 µg/ml Cy5-linked dsRNA targeting SmCB1, (B) 200 µg/ml recombinant mCherry protein or (C) 5 µl washed and packed human erythrocytes. For each image, the anterior end of the parasite is leftmost and times stated are post-preparation from cercariae. Both the Cy5-linked dsRNA and mCherry emit a strong fluorescent signal that quickly accumulates in the gut including in the two terminal cecal chambers. The arrow and arrowheads indicate the acetabular ‘gland ducts’ and acetabular ‘glands’, both being distinct from the developing gut. In (C), brown material, derived from the digestion of hemoglobin, highlights the parasite gut. Images were captured using: (A) a Zeiss LSM 510 META confocal microscope and a 633 nm laser for excitation; (B) a Zeiss Axiovert 40 CFL inverted microscope using the Filter Set 20 (ex-546; em-575-640) and connected to a Zeiss AxioCam HRc digital camera and (C) a Zeiss Axiovert 40 C inverted microscope connected to a Zeiss AxioCam MRc. Both AxioCAms were operated by AxioVision 40, version 4.5.0.0, software. Scale bars represent 20 µm.