Males are viable at 21^oC but do not survive at 29^oC. The oocyte nucleus migrates correctly to the antero-dorsal corner of the oocyte in homozygous females kept at 21^oC. However at 29^oC, 55% of oocyte nuclei fail to migrate in homozygous females, while the remaining 45% are similar to wild type. At 29^oC, mutant oocytes show a similar microtubule organisation to wild type prior to stage 7, but after this stage the microtubule organising centre (MTOC) fails to disassemble at the posterior and a second diffuse MTOC forms at the anterior (in wild-type the posterior MTOC disassembles and a diffuse MTOC forms at the anterior). This results in a symmetric organisation of microtubules, with their plus ends at the centre of the oocyte and their minus ends at the anterior and posterior. Posterior follicle cells often have a slightly disrupted morphology. After stage 6, mutant egg chambers have a double layer of follicle cells at the posterior of the egg chamber where the follicle cells are in contact with the oocyte. There is a twofold increase in the number of posterior follicle cells compared to wild type. The centrosomes of the posterior follicle cells point both apically and basally (in wild type they normally point to the apical surface). Homozygous oocytes surrounded by heterozygous follicle cells in mosaic egg chambers give rise to normal eggs. At 29^oC, 74% of eggs laid by homozygous females hatch and develop normally until the third instar stage, compared with a hatch rate of 94% at 21^oC. All the unhatched embryos have abdominal cuticle defects similar to that of osk mutants, while the eggs that hatch have normal cuticles. 48% of embryos lack pole cells. Only 11% of eggs laid by homozygous females have strong dorsoventral defects (such as a lack of dorsal appendages and a torpedo-like shape) and the other defective egg chambers found in the females degenerate after stage 10A.

Mer^ts1 has egg chamber | posterior & follicle cell phenotype, suppressible by grk^2E12