lethal | larval stage, with Rpn10t2.7
lethal | pupal stage, with Rpn10t2.7
The Pros54Pw+ mutation causes polyphasic lethality during the first larval instar (40% mortality), second larval instar (20%), third larval instar (13%) and pupal (27%) stages.
Pros54Pw+ mutants exhibit increased mortality compared to wild type in the first and second instar larval stage. The surviving larvae develop slowly, with the majority reaching maturity and pupariating 3-4 days later than wild-type larvae. Pros54Pw+ mutants, especially when late in pupariating, often have small internal organs compared to wild type. For example, the brain and ventral ganglion are about half the normal size. Only 27% of Pros54Pw+ mutants survive up to the end of larval development and form puparia. Such mutant puparia are smaller than the wild type and have a characteristic bent shape. The cuticle is softer, lighter in colour and less rigid than in the wild type. Some mutants only have pupal cuticles in the regions of the head and the external genitalia. About one-third of mutants secrete a complete pupal cuticle. However, the head eversion is mostly incomplete and the wings and legs are always smaller and shorter than in wild type. In half of Pros54Pw+ puparia only imaginal disc derivatives (head, thorax, adult appendages and the region of the external genitalia) secrete the pupal cuticle. All Pros54Pw+ puparia dry out in 1-2 days. The pupae never develop beyond this stage and even if kept wet to prevent drying out they are unable to develop further and die. Histolysis of the larval tissues apparently occurs and the fat body breaks up into single cells. Metamorphosis stops at this point because the inner organs of the adult are not formed and secretion of an adult cuticle never takes place. Neuroblast preparations from Pros54Pw+ larvae have a mitotic index of 4.1 compared to 1.7 in wild-type preparations. The metaphase to anaphase ratio is also higher in mutants (4.3 vs 2.2 in wild type). A significant proportion (24.6%) of Pros54Pw+ mitotic cells have over-condensed chromosomes which look similar to those seen in colchicine-induced mitotic arrest; mutants also have cells in prometaphase and metaphase that show no obvious centromeric connection between some of the sister chromatids. Additionally, some cells in anaphase display chromosome bridges and lagging chromosomes. In about 19% of Pros54Pw+ cells the major chromosomes are arranged in a circle with the centromeres pointing toward the centre and the fourth chromosomes in the middle of the circle, a pattern that may be caused by the formation of monopolar spindles. There is also a higher frequency of aneuploid and polyploid cells in Pros54Pw+ mutants (6% vs 0 in wild type). The presence of Pros54Pw+ in mutant pupae does not destabilise the regulatory complex of the 26S proteasome, nor does it interfere with the assembly of the regulatory complex and the catalytic core. Flies that are homozygous for Pros54Pw+ with one copy of Pros54t2.7 exhibit larval-pupal lethality. Flies that are homozygous for Pros54Pw+ with one copy of Pros54t2.8 are early larval lethals.
Rpn10Pw+ is a suppressor | partially of visible | adult stage phenotype of DebclUAS.Tag:HA, Scer\GAL4ptc.PU
Rpn10Pw+ is a suppressor of visible | adult stage phenotype of Mmus\BaxUAS.cGa, Scer\GAL4vg.PM
Rpn10Pw+ is a suppressor | partially of wing | adult stage phenotype of DebclUAS.Tag:HA, Scer\GAL4ptc.PU
Rpn10Pw+ is a suppressor of wing | adult stage phenotype of Mmus\BaxUAS.cGa, Scer\GAL4vg.PM
Rpn10Pw+ partially suppresses the adult wing phenotype of flies expressing DebclScer\UAS.T:Ivir\HA1 under the control of Scer\GAL4ptc.PU.
Rpn10Pw+ partially suppresses the notched wing phenotype observed in flies expressing Mmus\BaxScer\UAS.cGa under the control of Scer\GAL4vg.PM.
Rpn10Pw+ is rescued by Scer\GAL4da.G32/Rpn10UAS.Tag:FLAG
Rpn10Pw+ is partially rescued by Rpn10ΔK.UAS.Tag:FLAG/Scer\GAL4da.G32
Expression of Pros54ΔK.Scer\UAS.T:Zzzz\FLAG under the control of Scer\GAL4da.G32 shifts the lethal phase of Pros54Pw+ mutants to the pharate adult stage.
Expression of Pros54Scer\UAS.T:Zzzz\FLAG under the control of Scer\GAL4da.G32 rescues the lethality of Pros54Pw+.