Fig. 4. Morphology of chromosomes mutant for Z4. Tb⁺ homozygous mutant 3rd instar larvae were collected from the Z4-7.1/TM6,Tb stock and chromosomal squashes were stained with DAPI (A-C). Whole mount salivary glands from wild-type (D,G) and Z4 mutants transheterozygous for the alleles Z4-1.3/Z4-7.1 (E,H) were double stained with Sytox Green (D,E) and the Z4 antibody (G,H). Unfixed salivary glands dissected from larvae expressing the fusion construct BJ1-GFP (F) or from Z4-1.3/Z4-7.1 mutant larvae transgenic for BJ1-GFP (I) were analyzed by CLSM. In Z4 mutants a pertubation of chromosomes with the appearance of decondensed chromatin is evident (C,E,I).