egg1473/Df(2R)Dll-MP transheterozygotes are semi-lethal, display a low male:female ratio, and the few males die within 2-3 days; egg1473/Df(2R)ED4065 transheterozygotes are near lethal and no adult males eclose. egg1473/Df(2R)Dll-MP and egg1473/Df(2R)ED4065 transheterozygous adults exhibit shaky, uncoordinated movements and held-out wings that are incompletely expanded, as compared to controls; the locomotor and wing phenotypes of egg1473/Df(2R)Dll-MP transheterozygotes are more pronounced in males than in females. egg1473 homozygotes exhibit increased mortality during the pupal and pharate adult stages, but not during the larval stage, as compared to controls.
egg1473/Df(2R)Dll-MP transheterozygosity results in early oogenesis defects in the germarium, including a strong increase in the number of putative germ stem cells (exhibiting spectrosomes), a decreased number of germline cysts and an associated decrease in the number of egg chambers budding from the germarium, as compared to controls.
The generation of egg1473-homozygous germline clone cysts, either in larvae or adults, leads to an apparently normal progression of oogenesis until arrest and apoptosis of stage 5 egg chambers, as compared to controls. Although initially present in the germarium at similar frequency as controls, clonal egg1473 germline stem cells become progressively lost after clone induction; egg1473 follicle stem cell clones are initially less frequent in the ovary as compared to control clones, and also become progressively lost after clone induction.
Homozygous egg1473 mutant germ-line clones do not produce any eggs and the mutant egg chambers eventually degenerate.
egg1473/Df(2R)Dll-MP females have tiny ovaries consisting of germaria that do not bud off normal egg chambers. Many of these germaria lack recognisable regions and instead appear teardrop-shaped and are full of replicating germ cells and germline cysts that form no apparent egg chambers. Follicle and prefollicle cells are reduced in number and fail to completely encapsulate germline cysts. In the rare partially encapsulated cysts that do exist, germ cells show at least partial differentiation as nurse cells and oocytes.
egg1473/Df(2R)Dll-MP ovaries show an increased level of apoptosis compared to control ovaries. Apoptosis is seen in both somatic and germ cells within the mutant ovaries, but it is predominantly seen in the somatic cells. The majority of apoptotic somatic cells are found in the posterior region of the germaria, with the cells being found between incompletely budded egg chambers and anterior germ cells.
The frequency of germ cell mitoses in egg1473/Df(2R)Dll-MP ovaries is not significantly different from wild type, but the frequency of mitosis in somatic cells of the mutant germaria is significantly reduced compared to wild type.