Nucleotide substitution: A104T.
This mutation (nucleotide substitution: A104T) creates an ectopic AUG at +103 bp.
stnA6, stnB6 has decreased rate of movement phenotype
stnB6/stnA6 is an enhancer of neuromuscular junction phenotype of shi2
stnA6 stnB6 mutants show no decrease in synaptic vesicle density and no change in synaptic vesicle size at the larval neuromuscular junction (NMJ). Synaptic vesicle internalisation at the NMJ is delayed relative to wild type in stnA6 stnB6 mutants. The delay is even stronger in stnA6/stnA12 stnB6/stnB12 mutants. stnA6 stnB6 mutants are sluggish but do not show temperature-sensitive paralytic behaviour. At 28oC, stnA6 stnB6 mutant NMJs show only a marginal increase in the rate of synaptic depression as compared with wild type. The effect on depression remains slight even at 30oC. shi2 stnA6 stnB6 flies undergo complete paralysis in 2 minutes at 26oC. shi4 stnA6 stnB6 flies undergo complete paralysis in 2 minutes at 26oC. At 28oC, stnA6 stnB6 causes a marked enhancement of the weak neuromuscular junction depression seen in shi2 single mutants. At 30oC, there is no detectable effect of stnA6 stnB6 on depression.
Associated with: stnA6.
The "stnts" mutation affects the levels of both stnA and stnB proteins at the larval neuromuscular junction; the mutation does not alter presynaptic levels of stnA protein consistently, although reduced levels are frequently seen, and a marked reduction in stnB protein levels is seen.