Figure 3

Immunofluorescence analysis of MSP in nematode gonads. Dissected gonad preparations of parthenogenetic (P), hermaphroditic (H) and bisexual (B) nematodes were doubly stained for MSP (left panel) and DNA (DAPI, right panel). While sperm associated MSP is revealed in the hermaphrodites C. elegans (panel A) and the distantly related species Acrobeloides (herma) and Acrobeloides (bisex) (panels C, E; arrows), a signal cannot be spotted in the parthenogenetic species A. nanus and D. coronatus (panels G, I). Arrowheads in panel A, inset, indicate puncta at the surface of the -1 oocyte resembling extracellular MSP as published previously [49]. The inset of panel A and panels G-J are from the same experiment, panels A-F from another. The photographs of parthenogenetic animals were overexposed to demonstrate the lack of staining, and their gonadal shape is outlined for better orientation. sp: sperm. st: spermatheca. int: intestine. emb: embryo. -1, -2, -3: proximal oocytes, -1 is most proximal. All gonads are oriented with proximal to the left. Bar: 20 μm.