Triethylamine is the active ingredient in FlyNap, a product for anesthetizing "Drosophila melanogaster". They were shown to be able to visually distinguish between different mutations of "Drosophila melanogaster". Paraquat also induces oxidative stress in invertebrates such as "Drosophila melanogaster". Another virus is Nora virus from "Drosophila melanogaster". Period (per) is a gene located on the X chromosome of "Drosophila melanogaster". The discovery of mitotic recombination came from the observation of twin spotting in "Drosophila melanogaster". Many strains have been isolated from the haemolymph of "Drosophila melanogaster" fruit flies. This shows that PKA is required for conditioned learning in "Drosophila melanogaster". Balancer chromosome was primalrily used for studies in "Drosophila melanogaster" genetics. Overexpression of the "GADD45" gene in the "Drosophila melanogaster" nervous system significantly increases longevity. Multiple studies have been conducted concerning transgenesis in "Drosophila melanogaster", the fruit fly. The signalling pathway is also crucial for eye development in the fruit fly ("Drosophila melanogaster"). Neurogenesis has been best characterized in model organisms such as the fruit fly "Drosophila melanogaster". Toxic semen is most associated with "Drosophila melanogaster" fruit flies. FlyBase annotates the entire "Drosophila melanogaster" genome.