Cytoplasmic dumping is blocked in homozygous egg chambers. The cytoplasmic actin cytoskeleton of nurse cells shows major disruptions, while the cortical actin appears normal.

Chromatin organization in the pseudonurse cells differs from wild type. Instead of showing endopolyploidy, the chromosomes are somewhat polytenised, with a minority showing complete polytenisation.

Differentiated egg cysts are arrested at late oogenic stages.

DIF (differentiated) class allele. The polyploid chromosomes within the nurse cells are dispersed and not polytenised.

Allows maturation of the oocyte to proceed in most egg chambers until late stages of oogenesis. Double mutants with egl mutants display degenerate egg chambers, mutant phenotypes are cumulative.

Spermatogenesis normal but mating behaviour fails because wild type females refuse to react to the courtship attempts of mutant males. Effect is not absolute, and depends on allele (there is a strong correlation between male sterility and severity of impairment in the female phenotype) and varies between affecting 6.7% (otu¹⁴) and 86.6% (otu¹²) of mutant males.

Homozygous females have a differentiated ovary phenotype, hemizygous females have a quiescent ovary phenotype.

95.5% of homozygous ovarioles produce nurse cell/oocyte syncytia, and 2.5% have tumorous oogonia. Most otu¹¹/otu⁵ female flies are fertile. otu¹³/otu⁵ female flies are poorly fertile.

Differentiated allele; 95.5% of homozygous ovarioles contain differentiated cystocytes forming oocytes. 71% of hemizygous ovarioles are quiescent.

differentiated; ovarian chambers with pseudonurse cells or nurse cell/oocyte synctia