Fig. 2.

Endogenous Plugin localization in the MAGs. a Transmission electron micrograph of the boundary between anterior (ant) and posterior (post) MAG compartments in wild type males. Red box indicates area magnified in panel (b), white box indicates area magnified in panel (d). Inset image provided for orientation within MAGs and approximate area magnified. b The anterior compartment has peripherally located nuclei (nuc) and contains electron-dense vesicles that fill the lumen (lum). The central aedeagus (aed) is marked for orientation. White box indicates area magnified in (c). c Plugin is localized within the electron-dense secretory vesicles by gold-labelled α-Plugin (white arrowheads). d Vesicles within the anterior (ant) and posterior (post) compartments are different in size and electron density, suggesting different contents. White box indicates area magnified in (e). e Plugin is localized only within the more electron-dense secretory vesicles of the anterior compartment by gold-labelled α-Plugin (white arrowheads). Scale-bars: (a), 5 μm; (b, d), 2 μm; (c, e), 0.5 μm