Microtubules in hindgut cells in the papillate region 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 papillate region B overlay of epifluorescence and DIC images obtained on paraffin sections showing microtubules in green (AlexaFluor 488) and cell nuclei in blue (DAPI). Image depicts area denoted by the frame B in image A C 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 image B. The white dashed lines in figure C outline the apical and basal surface of hindgut epithelium D electron micrograph showing equivalent area as denoted by frame D in image C. Arrows point to microtubule bundles in the cytosol between the infoldings of apical plasma membrane which are indicated by the arrowheads E electron micrograph showing equivalent area as denoted by frame E in image C. Arrowheads point to numerous cross-sectioned microtubules in the vicinity of septate junctions. Arrows point to longitudinally sectioned apico-basal microtubules. Abbreviations: HC – hemocoel; HE – hindgut epithelium; HL – hindgut lumen; M – mitochondria; SJ – septate junctions.