79% of embryos lacking both maternal and zygotic wun and wun2 function (derived from females carrying homozygous double mutant wun⁴⁹ wun2^EP2650ex34 germline clones mated to wun wun2 double mutant males) have aberrant tracheal morphology. Breaks in the dorsal trunk plus bulbous chitin accumulation throughout the dorsal and lateral trunk and transverse connectives are seen.

Very few animals which lack both maternal and zygotic wun and wun2 function (derived from females containing double mutant wun⁴⁹ wun2^EP2650ex34 germline clones mated to Df(2R)wun-GL/+ or Ab(2;?)wun^CE/+ males) survive to adulthood. This lethality is only partially rescued by expression of either wun^{Scer\UAS.T:Avic\GFP-EGFP} or wun2^{Scer\UAS.T:Hsap\MYC} under the control of Scer\GAL4^btl.PS.

Embryos derived from females carrying homozygous wun⁴⁹ wun2^EP2650ex34 germline clones crossed to wild type males are lethal in late embryogenesis. These embryos form a wild type number of germ cells that are correctly positioned in the midgut pocket at stage nine. wun⁴⁹ wun2^EP2650ex34 mutant germ cells fail to individualise, but are still able to cross the midgut as a cluster, although this occurs at stage 11 rather than stage 10. However they fail to migrate further into the overlying mesoderm and eventually undergo cell death. Cell death is first observed at stage 10 and by stage 15/16 the number of germ cells is reduced to on average 1.4 (compared to approximately 21 in wild type). The remaining wun⁴⁹ wun2^EP2650ex34 mutant germ cells also exhibit defects in distribution to the gonads. When either 2 or 4 germ cells are present the germ cells distribute randomly between the two gonads, whereas when 3 germ cells are present there is a significant bias towards all germ cells migrating to the same gonad.

Expression of wun^Scer\UAS.cZa under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} rescues the germ cell death in embryos derived from females carrying homozygous wun⁴⁹ wun2^EP2650ex34 germline clones and wild type males.

Expression of wun2^{Scer\UAS.T:Hsap\MYC} under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} rescues the germ cell death in embryos derived from females carrying homozygous wun⁴⁹ wun2^EP2650ex34 germline clones and wild type males.

Expression of wun2^{H326K.Scer\UAS.T:Hsap\MYC} under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} is unable to rescue the germ cell death seen in embryos derived from females carrying homozygous wun⁴⁹ wun2^EP2650ex34 germline clones and wild type males.

Embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones and Df(2R)wun-GL males have a less severe germ cell death phenotype than embryos produced when females with wun⁴⁹ wun2^EP2650ex34 germline clones are crossed to wild type males (10.6 germ cells on average compared to 1.4). The surviving germ cells are found exclusively within the midgut and fail to individualise at stage 10. Most germ cells do not cross the midgut epithelium, instead remaining in a clump inside the midgut pocket. Occasional germ cells detach from the clump and migrate within the midgut with normal amoeboid-like motion.

Loss of maternal shg^A9-49 is unable to rescue the germ cell migration defects seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones crossed to Df(2R)wun-GL males. Germ cell dispersal can be seen at stage 10.

Expression of Rho1^N19.Scer\UAS in the germline under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} rescues the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones. No germ cells can be detected outside of the gut.

Expression of Rac1^V12.Scer\UAS in the germline under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} rescues the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones. No germ cells can be detected outside of the gut.

Expression of Rac1^N17.Scer\UAS in the germline under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} does not rescue the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones.

Expression of Rho1^V14.Scer\UAS in the germline under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} does not rescue the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones.

Expression of Rho1^Scer\UAS.cMa in the germline under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16} does not rescue the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones.

Homozygous srp² rescues the germ cell death seen in embryos derived from females carrying wun⁴⁹ wun2^EP2650ex34 germline clones. The surviving germ cells are found in a tight clump inside the gut but also frequently in loosely associated groups outside of the gut. These germ cells are of normal size and morphology. Heterozygous srp² is unable to rescue the phenotype.

Wild-type stage 5 germ cells transplanted into the posterior pole of stage 5 wun⁴⁹ wun2^EP2650ex34 host embryos does not prevent germ cell death from occuring at stage 14. No correlation can be seen between cell transplanted and the number of surviving germ cells.

The rate of photoreceptor degeneration seen in rdgA³ flies is not slowed if they also carry wun2^EP2650ex34.

The reduced number of germ cells seen in stage 15 embryos derived from wun2^EP2650ex34/Df(2R)wun-GL females is not suppressed if the embryos are zygotically mutant for abd-A^46.51.

The germ cell death seen in embryos with a wun2⁺ soma which are derived from wun2^EP2650ex34/Df(2R)wun-GL females is rescued by expression of wun^Scer\UAS.cZa under the control of Scer\GAL4^{nos.UTR.T:Hsim\VP16}.