Wild-type females crossed with males expressing gudu^GD11556 under the control of either Scer\GAL4^tub.PU or Scer\GAL4^{bam.T:Hsim\VP16} lay a similar number of eggs as control females crossed with wild-type males. However, none of the eggs hatch.

The hatching rate of eggs laid by females expressing gudu^GD11556 under the control of Scer\GAL4^tub.PU crossed with wild-type males is normal.

The testes of males expressing gudu^GD11556 under the control of Scer\GAL4^tub.PU have normal onion-stage spermatids, and elongated spermatids are seen. However, the mutant testes contain spermatid bundles with little mobility, in contrast to the motile and individualised sperm seen in wild type. The individualisation complexes are disorganised and diffuse compared to wild type.

Spermatids are bundled, rather than individualised, in males expressing gudu^GD11556 under the control of Scer\GAL4^{bam.T:Hsim\VP16}, and the individualisation complex appears disorganised.

Adults expressing gudu^GD11556 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 of gudu^GD11556 under the control of Scer\GAL4^elav.PLu (in the presence of Dcr-2^Scer\UAS.cDa to increase the efficiency of RNAi) results in viable flies or partial lethality, depending on the particular P{GD11556} insertion line used.