Fig 7. Temperature-sensitive period for GnT1 triple mutant phase 2 DTC migration errors.

A temperature shift experiment similar to that of Fig 3, but limited to shifting only L1s (based on the Fig 3ev821 results) was performed for the GnT1 triple null mutant scored for all 3 kinds of VCPs by low magnification stereomicroscopy. Visible VCPs are not as frequent as phase 2 defects scored by D.I.C. in the GnT1 triple mutant, probably because the distal arm return along the proximal arm is typically much shorter (creating a much smaller VCP) in the GnT1 triple than in ngat-1(ev821). Neither the ngat-1(ev821) nor the GnT1 triple null mutant can prevent, reverse, or compensate a phase 2 DTC migration failure induced by embryonic growth at 25°C if shifted back to 16°C during the first larval (L1) phase, whereas embryonic growth at 16°C leads to largely normal DTC migration that cannot be reversed by a shift to 25°C during the first larval (L1) stage.