Fig. 4. Loss of PAR-1 destabilises MTs. (A) A par-1 clone in a stage 10 egg chamber that has been treated with the MT-depolymerising drug, colcemid, and then fixed under optimised conditions and stained for -Tubulin. The par-1 mutant cells lack MTs, whereas the wild-type cells show a similar MT organisation to untreated cells. (B) Cold shock for 1 hour leads to the disappearance of the MTs in par-1 clones. Note that the cold shock also reduces the nuclear localisation of nls-GFP, and partially disperses the cortical bundles of MTs in wild-type cells. (C) Cold shock followed by 5 minutes of recovery at room temperature. The MTs have started to re-grow in mutant cells, but are still less dense than in the wild-type cells. (D) Cold shock followed by 10 minutes of recovery at room temperature. The mutant cells now contain more MTs than wild-type cells, as in untreated ovaries. GFP, green; -Tubulin, red.