mst2 rod1100 double mutant larvae show a higher frequency of ana-telophases in the brain than mst2 single mutants. The ana-telophase figures of the double mutants show chromosome segregation defects that are much more severe than those seen in rod1100 single mutants.
The brains of mst2 Sas-4unspecified double mutant larvae have a very high mitotic index, with most dividing cells arrested in metaphase with highly contracted chromosomes. More than 95% of metaphases lack centrosomes and these metaphases have very peculiar 'spindles': 34% are devoid of microtubules arrays, 4% have small and disorganised bipolar spindles and 62% have acentrosomal microtubule arrays (AMTAs) resembling monopolar spindles. The AMTAs are always associated with metaphase chromosomes, with some microtubules terminating at the chromosomes, and others extending beyond them.