embryonic dorsal group branch & filopodium
The opposing tracheal phenotypes of awdj2A4/+ and Catsup26/+ single heterozygous embryos (ectopic migration and lack of migration respectively) are both partially suppressed in awdj2A4/+ Catsup26/+ double heterozygous embryos.
A awdj2A4 heterozygous background strongly enhances both the penetrance (from 46% of embryos to greater than 80% of embryos) of the ago1/ago3 mutant dorsal trunk phenotype and its expressivity among affected embryos. These embryos also show a much more severe disruption of the entire tracheal system compared to ago1/ago3 mutants.
68.8% of btlH82Δ3/+; awdj2A4/+ transheterozygous embryos have normal tracheal systems, compared to 33.3% in awdj2A4/+ embryos. 17.5% of these transheterozygotes have tracheal phenotypes resembling those seen in 66.7% of awdj2A4/+ embryos, with the remainder having tracheal phenotypes resembling those seen in btlH82Δ3/+. The tracheal system phenotypes of shi1 homozygous embryos (collected at the permissive temperature (25oC) for 7 h and then shifted to 34oC for another 7 hours) are dominantly enhanced by awdj2A4 : the penetrance of the most severe phenotypic class is increased from 1.2% to 33.2% by the presence of awdj2A4/+. (Note, these sever phenotypes are never observed in awdj2A4/+ embryos raised under the same conditions). The relatively mild tracheal phenotypes seen in awdj2A4/+ embryos are enhanced by btlScer\UAS.T:Avic\GFP-S65T with Scer\GAL4btl.PS so that 20% have tracheal phenotypes as severe as the majority awdj2A4 homozygotes compared to none with awdj2A4/+ alone.
L. and Y. Jan.