Expression of Ctf4^GD4433 under the control of Scer\GAL4^Act.PU does not results in larval or pupal lethality, but only 41.2% of animals succeed in eclosing. Of those animals that eclose, all are female and are severely emaciated compared to wild type and they show 100% lethality after less than three days.

Larval brain tissue expressing Ctf4^GD4433 under the control of Scer\GAL4^Act.PU shows a significant reduction in mitotic index compared to controls. Mitotic figures with premature sister chromatid separation are seen and significantly more cells are seen in S-phase than in controls.

Salivary gland polytene chromosomes are reduced in thickness by 43.4% compared to controls.

Expression of Ctf4^GD4433 in females using heat shock to drive expression from the heat-shock promoter present in the construct results in 69% of the embryos laid by these females showing asynchronous division and anaphase bridging during the syncytial phase. 17.4% of stage 7-8 egg chambers degenerate in females expressing Ctf4^GD4433 using heat shock.

53% of larvae expressing Ctf4^GD4433 under the control of Scer\GAL4^Act.PU survive compared to controls after treatment with hydroxyurea.

Adults expressing Ctf4^GD4433 under the control of Scer\GAL4^elav.PLu (in the presence of Dcr-2^Scer\UAS.cDa to increase the efficiency of RNAi) do not show a significant defect in avoidance of noxious temperature (46[o]C) compared to control flies.

Expression under the control of Scer\GAL4^pnr-MD237 may result in semi-lethality, depending on the insertion line used.

Expression under the control of Scer\GAL4^pnr-MD237 results in the absence of 0% or 70-80% of the Scer\GAL4^pnr-MD237-expressing area of the notum, depending on the insertion line used.