FLPase mediated recombination between the progenitors (PBac{WH}CG9171f04201 and PBac{WH}f06711) results in deletion of obst-E, CR31912, and parts of CG9171 and CG11030.
anterior pupal spiracle | prepupal stage (with obst-EKO), with Scer\GAL4Act5C.PU, obst-EUAS.b
procuticle | third instar larval stage (with obst-EKO), with Scer\GAL4Act5C.PU, obst-EUAS.b
obst-ECPTI002377/obst-EDel transheterozygous pupae are longer and thinner than wild-type and have significantly higher axis ratio (AR, length/width).
obst-EKO homozygotes and obst-EKO/obst-EDel transheterozygotes are first instar larval lethal. No apparent morphological defects are observed in the cuticle of the obst-EKO or obst-EKO/obst-EDel mutant first instar larvae, but the hindgut (although morphologically normal during embryogenesis) protrudes out of the anus in these larvae - likely constituting the primary reason for their lethality.
Scer\GAL4Act5C.PU-driven expression of obst-EScer\UAS.b rescues the lethality of obst-EKO/obst-EDel transheterozygotes but the 'rescue' pupae show body shape defects (are thinner and longer than controls) due to failed shape change and contraction upon dehydration of the larval cuticle during metamorphosis. The prepupae show normal internalization of the anterior segments but the anterior spiracles fail to evert and remain encapsulated within the puparium. In contrast to wild-type, no ridges are observed on the inner surface of third instar larval cuticle of the mutant animals and the surface appears essentially flat with the exception of a narrow lateral region where some of the ridging is partially preserved. Although the general three-layer organization of the cuticle is maintained, unlike the lamellae in wild-type, the lamellae in the procuticle layer of the mutants are flat, of constant thickness and tend to contain unidirectional arcs. No apparent morphological aberration are observed in the cuticle of first or second instar larvae.
obst-EDel/obst-ECPTI002377 is rescued by Scer\GAL4Act5C.PU/obst-EUAS.a
obst-EDel/obst-EKO is rescued by Scer\GAL4Act5C.PU/obst-EUAS.a/obst-EUAS.b
obst-EDel/obst-ECPTI002377 is partially rescued by Scer\GAL4Act5C.PU/obst-Ea.EGFP
obst-EDel/obst-EKO is partially rescued by Scer\GAL4Act5C.PU/obst-EUAS.a
obst-EDel/obst-EKO is partially rescued by Scer\GAL4Act5C.PU/obst-EUAS.b
obst-EDel/obst-EKO is partially rescued by Scer\GAL4Act5C.PU/obst-Ea.EGFP
obst-EDel/obst-ECPTI002377 is not rescued by Scer\GAL4Act5C.PU/obst-EUAS.b
The pupal shape defects (pupae are longer and thinner compared to wild-type and have higher axis ratio) characteristic for obst-ECPTI002377/obst-EDel transheterozygotes is rescued by expression of obst-EScer\UAS.a or obst-Ea.T:Avic\GFP-EGFP but not obst-EScer\UAS.b under the control of Scer\GAL4Act5C.PU in the mutant background.
Scer\GAL4Act5C.PU-driven expression of obst-EScer\UAS.a only weakly rescues the larval lethality of obst-EKO/obst-EDel transheterozygotes, however the pupae of the escapers have body shape with an axis ratio only slightly (though significantly) increased compared to wild-type. On the other hand, expression of obst-EScer\UAS.b does rescue the obst-EKO/obst-EDel larval lethality efficiently but the rescued pupae are abnormal in shape (despite having normal body shape during the larval stages). Simultaneous expression of obst-EScer\UAS.b and obst-EScer\UAS.a rescues both the lethality and the pupal shape defects of obst-EKO/obst-EDel animals.