Microtubules in hindgut cells in the anterior chamber of adult P. scaber A overlay of epifluorescence and DIC images obtained on paraffin section showing microtubules in green (AlexaFluor 488) and cell nuclei in blue (DAPI). Image depicts cross-section across the anterior chamber B image of immunofluorescent-labelled microtubules in green on LR-White section. Image depicts equivalent area as denoted by frame B in image A. Arrowheads point to transcellular microtubule bundles in typhlosole cells oriented perpendicular to the apical cell surface. Arrow points to short profiles of microtubule bundles present in the apical cytosol of wide cells around the typhlosole channels. The white dashed lines outline the apical and basal surface of epithelial cells C overlay of epifluorescence and DIC images obtained on paraffin section showing microtubules in green (AlexaFluor 488) and cell nuclei in blue (DAPI). Image depicts equivalent area as denoted by the frame C, D in image A D overlay of epifluorescence images obtained on semithin LR-White section showing microtubules in green (AlexaFluor 488) and cell nuclei in blue (DAPI). Image depicts equivalent area as denoted by the frame C, D in image A. The white dashed lines outline the apical and basal surface of hindgut epithelium E electron micrograph showing equivalent area as denoted by frame E in image D. Arrows point to abundant microtubule bundles near the lateral plasma membrane (arrowheads) F higher magnification of an area denoted by frame F in image E. Arrows point to bundled individual microtubules near the lateral plasma membrane (arrowheads). Abbreviations: HC – hemocoel; HE – hindgut epithelium; HL – hindgut lumen; T – typhlosole; TC – typhlosole channels.