Q87term | Tsc1-PA
Site of nucleic acid difference inferred by FlyBase based on reported amino acid change
The introduction of Tsc1Q87X clones into the neighborhood of Pten117 clones reduces the overgrowth phenotype, under starvation conditions. Thus, even when neighboring with a tissue that also has a growth advantage, Pten clones themselves experience competition for common resources.
A Tsc1Q87X mutant clone background results in the gradual loss of Tsc1Q87X NdsRNA.P.Scer\UAS double mutant intestinal stem cell clones from the epithelium, as only 11.3% intestinal stem cell clones are maintained by 21 days after clone induction, compared with a 94.8% maintenance rate for NdsRNA.P.Scer\UAS single mutants. There is no significant increase in apoptosis in these double mutant cells. At 2 weeks after clone induction, when significant numbers of Tsc1Q87X NdsRNA.P.Scer\UAS double mutant intestinal stem cells have been eliminated, many mutant cells have detached from the epithelium and are found in the lumen. Some delaminate as single cells while others delaminate in clusters.
Tsc1Q87X NdsRNA.P.Scer\UAS double mutant intestinal stem cell (ISC) clones are larger than wild-type clones. They are Dl-positive, indicating that they are ISC-like, remain diploid, and are negative for the epithelial cell marker nub. Enteroendocrine cell-like tumours are barely observed in these double mutants.
Unlike either nero1 or Tsc1Q87X mutant clones, Tsc1Q87X nero1 double mutant clones cannot be recovered. Tsc1Q87Xfully suppresses the autophagic defect seen in nero1 mutant animals. However, this epistatic relationship is reveresed in other contexts such as larval growth and developmental timing. Tsc1Q87X mutant larvae appear to undergo precocious development. However, this precocious development is suppressed in Tsc1Q87X nero1 double mutant larvae.
The second instar lethality of homozygous Tsc1Q87X is rescued to early pupal stages in a S6kl-1 homozygous background, however, the larvae are small and severely delayed in development. In contrast, in a S6kl-1/+ background Tsc1Q87X homozygous animals develop to early pupal stages with little developmental delay, and are significantly larger than wild type. The second instar lethality of homozygous Tsc1Q87X is rescued to adulthood (18.5%) or pupal stages (82.5%) by heterozygosity for Tor2L1. The second instar lethality of homozygous Tsc1Q87X is rescued to adulthood (62%) or pupal stages (93%) by heterozygosity for both S6kl-1 and Tor2L1. The rescued animals are slightly larger than wild-type flies, with overall patterning appearing normal. The rescued females are semi-fertile when crossed to wild-type males, whereas the rescued males are fully fertile when crossed to wild-type females. Eye overgrowth caused by somatic clones of Tsc1Q87X in the developing eye and the increase in ommatidia size within the clones are suppressed in homozygous S6kl-1 animals.