Common posterior Distal Tip Cell (DTC) trajectories in ngat-1(ev821) mutant animals.

Lateral view of the posterior gonad arm in L4 hermaphrodite animals by D.I.C. microscopy. In all panels, anterior is left, dorsal is up. (A) The 2 DTCs are born in ventral mid-body (in position of future vulva marked by triangle) and normally migrate post-embryonically in 3 phases [(1) thru (3)] to shape the developing U-shaped gonad arms. (B) Some ngat-1(ev821) animals grown at 25°C have a normal posterior DTC migration as in panel A, while many have an unc-6 mutant-like phase 2 failure with phases 2 and 3 executed on the ventral side (panel B), while others (panel C) show a partial return to mid-body before migrating dorsally. To the right of panels B and C are the predicted corresponding ventral clear patch (VCP) phenotypes visible by low magnification stereomicroscopy (asterisk marks partial VCP in panel C). Scale bar in panel A (for A-C) is 50 μm.