Figure 4: ISH results for expression of Wolbachia surface protein gene (wsp) in adult Brugia malayi worms. ISH signals were detected in both adult female (A-C) and adult male (D) worms. (A) wsp expression in lateral cord and some but not all developing oocytes in ovaries; (B) wsp expression in lateral cord and early stage embryos (morula stage); (C) lateral cords are labeled, but late stage embryos (stretched microfilariae) are not labeled; (D) only lateral cords are labeled in adult males. Abbreviations: i: intestine; lc: lateral cord; ov: ovary; ut: uterus; mf: stretched microfilariae; sp: developing sperm; em: embryo; scale bar: 20 μm.