Insertion in exon 1 in the 5' untranslated region, 33bp upstream of the translation start site.
Approximately 25% of homozygotes develop to third instar larvae.
Approximately 35% of Mob4EY23407/Df(2R)42 animals develop to third instar larvae, while approximately 10% pupate but do not eclose.
15% of Mob4EYΔL3/Mob4EY23407 animals develop to the third larval instar, 3% pupate but do not eclose.
Third instar mutant larvae have a "tail-flip" phenotype.
Mob4EY23407/Df(2R)42 and Mob4EYΔL3/Mob4EY23407 third instar larvae have supernumerary boutons at the neuromuscular junctions of muscles 6/7 and 4 compared to controls.