Figure 1

Glands of the cercaria of T. regenti. A, schematic figure of the cercaria with highlighted glands; postacetabular glands in green, circumacetabular glands in pink, head gland in blue. B, z-section from CM of cercarial head organ stained with Alexa Fluor^® 488 and Cy3-azide; secretory vesicles of postacetabular ducts express bright fluorescence; head gland is in greenish grey. C, three-dimensional model of acetabular glands; Cy3-azide and Alexa Fluor^® 488 stained cercaria was employed for the reconstruction; postacetabular glands are in green, circumacetabular glands in red; wide arrow shows acetabulum, thin arrow points to the strangulation of duct bundles entering muscular conus of the head organ (also see Additional File 1). D, visualization of cercarial circumacetabular glands by alizarin and fluorescence microscopy; cercaria was anaesthetized by Procain, acetabulum is exserted; marked are the posterior and anterior circumacetabular gland cells on the right side of cercaria. E, combination of autofluorescence and staining by FITC-phalloidin of the cercaria in CM; arrow points to the area where gland ducts enter the muscular conus; projection series. F, three-dimensional model of cercarial head gland; lobated cercarial head gland (in dark blue) with the three bundles of acetabular gland ducts on each side running through the head gland cell within the head organ (each bundle coloured separately). HG, head gland; dPA, ducts of postacetabular glands; CA-p and CA-a, posterior and anterior circumacetabular cells, respectively; PA and CA, postacetabular and circumacetabular glands, respectively; MC, muscle conus; A, acetabulum.