Gaucher disease (GD) is the most common of the lysosomal storage disorders and 
is caused by defects in the GBA gene encoding glucocerebrosidase (GlcCerase). 
The accumulation of its substrate, glucocylceramide (GlcCer) is considered the 
main cause of GD. We found here that the expression of human mutated GlcCerase 
gene (hGBA) that is associated with neuronopathy in GD patients causes 
neurodevelopmental defects in Drosophila eyes. The data indicate that 
endoplasmic reticulum (ER) stress was elevated in Drosophila eye carrying 
mutated hGBAs by using of the ER stress markers dXBP1 and dBiP. We also found 
that Ambroxol, a potential pharmacological chaperone for mutated hGBAs, can 
alleviate the neuronopathic phenotype through reducing ER stress. We demonstrate 
a novel mechanism of neurodevelopmental defects mediated by ER stress through 
expression of mutants of human GBA gene in the eye of Drosophila.