eye disc & mitotic cell cycle
The reduced size of the posterior compartment of the wing that is seen in animals expressing crolScer\UAS.cMa under the control of Scer\GAL4en-e16E is suppressed if they are also heterozygous for E2f91.
The ectopic genomic replication that is seen in the follicle cells of stage 13 E2f2329/E2f21-188 egg chambers is partially suppressed by E2f91/+; 55% of the double mutant egg chambers show a 50% reduction in the number of follicle cells exhibiting ectopic genomic replication compared to the single mutant egg chambers.
The addition of E2f276Q1/Df(2L)G5.1 to E2f91/E2frM729 flies almost completely suppresses the E2f91/E2frM729 phenotypes - mutants develop normally without any significant delay in larval growth, reach pupal stage and finally die as mid- or late pupae. The pattern of DNA synthesis in eye discs is largely normal. The addition of Dpa2/Df(2R)vg-B to E2f91/E2frM729 flies almost completely suppresses the E2f91/E2frM729 phenotypes - mutants develop normally without any significant delay in larval growth.
The early larval lethality of Rbf14/Y males is partially suppressed by E2f91/E2f164; these larvae survive to the third larval instar stage. Their development is delayed by about 2 days compared to wild type, and most of the larvae can develop further into pupae. The Rbf14/Y ; E2f91/E2f164 larvae and pupae are slightly smaller than wild type. Some develop into very late stage pupae with adult structures (such as eyes, legs, wings, cuticle and bristles) but they cannot completely eclose. There are two differences in the pattern of BrdU incorporation in the eye discs of Rbf14/Y ; E2f91/E2f164 larvae compared to wild type. Firstly, the G1 arrested region in the morphogenetic furrow is much narrower, cells just anterior to the morphogenetic furrow are not arrested in G1, instead they become part of the first mitotic wave. Secondly, some cells posterior to the second mitotic wave still incorporate BrdU. Rbf14/Y ; E2f91/E2f164 eye discs are slightly smaller than normal. There is increased cell death (seen just anterior to the morphogenetic furrow) in these eye discs compared to those of wild-type or E2f91/E2f164 larvae. Adult Rbf14 flies rescued by expressing Rbfhs.PD during the first 3 days after egg laying show a number of alterations in adult structures such as abnormal macrochaetae on the notum and rough eyes. These adult phenotypes are also rescued without heat shock if the flies are also carrying E2f91/E2f164. The larval lethality of E2f91/E2frM729 animals can be suppressed by Rbf120a/Rbf14; the larvae develop into large late third instar larvae and many can pupate. Some Rbf120a/Rbf14 ; E2f91/E2frM729 animals can develop into pharate adults with adult eyes, legs and wing structures. The development of these larvae is significantly retarded compared to wild-type larvae, with the earliest pupae observed at around day 11 after egg laying. The normal pattern of DNA replication in the optic lobe region is restored in E2f91/E2frM729 larvae that are also carrying Rbf120a/Rbf14. In Rbf120a/Rbf14 ; E2f91/E2frM729 eye discs the overall pattern of DNA replication is normal. No significant cell death is seen in these eye discs. In late third instar discs there are about 25 rows of developing photoreceptor cells (as in wild-type discs) but there are much fewer cells anterior to the morphogenetic furrow than in wild type.
Dominantly enhances the rough eye phenotype and reduction in the number of cells entering S phase posterior to the morphogenetic furrow seen in CycEJP homozygotes.