Fig. 1. (A) Schematic representation of the gonad structure of a wild-type hermaphrodite. The U-shaped gonad lobes are rotationally symmetrical around the dorsoventral axis at the center of the body. DTC, distal tip cell. The dorsal side is upwards. (B) Schematic illustration of the time course and pattern of gonad lobe extensions in wild-type hermaphrodites (lateral view). The DTCs lead the extension of the gonad lobes in three migration phases. First, the DTCs are generated at the ventral mid-body during the L2 stage and migrate in opposite directions along the ventral body wall muscle (phase I). They then turn orthogonally and migrate over the lateral hypodermis towards the dorsal muscles during the L3 stage (phase II). After reaching the dorsal side, the DTCs turn again and migrate towards the midbody along the dorsal body wall muscles during the L4 stage (phase III). The ventral midbody is marked with an asterisk.