rlSem mutants exhibit significant reductions in NMJ size and numbers of pre-synaptic active zones and post-synaptic GluRIID fields. The areas of the active zones and GluRIID fields are unchanged compared with controls.
Heterozygous females show a weak dominant sterility; 10.2% of the eggs laid by these females fail to hatch and 20.0% of these nonviable embryos have defects similar to those associated with gain-of-function alleles of tor.
The sev signalling pathway is activated, even in the absence of the boss inducing signal: flies show positive phototaxis towards UV light. Eyes show multiple R7 cells. Embryos from heterozygous females show reduced numbers of abdominal segments though the head skeleton and filzkorper do develop. As for dominant Egfr mutants, heterozygotes have extra wing vein material.
Expressing Dsor1GD9123 under the control of Scer\GAL4en.PU in a rlSem/+ background results in notched wings with a mix of ectopic and lost vein tissue. Wings did not show creases, or the "droopy" phenotype.
The increase in midline glial cells seen in rlSem mutant embryos is slightly enhanced by Wunspecified/Wunspecified (from 6 (n=231) to 6.6 (n=91)). The reduction in midline glial cell numbers seen in commΔe39 mutant embryos is suppressed in double mutants with rlSem. These rescued midline glial cells are scattered throughout the midline, which lacks axons in these animals.
rlSem/+ alone is not sufficient to rescue the reduced eye and head phenotypes of flies that are homozygous for Ras85Dx7b in the eye disc. However, the addition of Ras85DD38E in combination with rlSem results in a substantial rescue of the Ras85Dx7b eye and head size phenotypes; differentiated photoreceptor cells are seen and a substantial fraction of the ommatidia contain the full complement of photoreceptors.
At 25[o]C rlSem dominantly enhances most of the hyperplastic growth seen in Ras85DV12.Scer\UASScer\GAL4dpp.blk1 wing discs resulting in a much larger disc with severe disruptions of morphology. Ras85DV12.G37.Scer\UASScer\GAL4dpp.blk1 and rlSem act synergistically to produce a small amount of hyperplastic growth in third instar wing discs. Mutants die as pharate adults at 25[o]C and have deletions of tarsal segments and extra wing vein material along L3.
Eyes show multiple R7 cells, even in a sev- mutant background. rlSem suppresses the reduced viability associated with phl12, phl1 and phl107, and the eye phenotype of phl1. Homozygous tll1 embryos from rlSem/+ mothers have a tll mutant phenotype. The extra wing vein phenotype of heterozygotes is enhanced in transheterozygotes with dominant Egfr alleles. Flies heterozygous for EgfrE3 or EgfrE1 and rlSem have smaller eyes than EgfrE3 or EgfrE1 heterozygotes alone.