Progress in molecular mechanism of olfaction in Drosophila melanogaster

Drosophila melanogaster is one of the most popular animal models for biological research,especially for studies on olfaction.Recent advancement in Drosophila olfactory research uncovered much about the mechanisms underlying odor detection and discrimination,sensory transduction,coding,olfactory memory,etc.It showed that～1 300 Drosophila olfactory receptor neurons(ORNs)express a total of 62 different olfactory receptor proteins(ORs)to detect all chemical molecules a fly senses.The odorant ligands of many Drosophila ORs have been elucidated:General odors,such as fruit odors,are encoded by combinations of different ORs;whereas pheromones that elicit mating and social interactions are encoded by single specific OR.Odor information is transformed into electrical neural signal in ORN,then the signal is relayed to the antennal lobe(AL)along the axon of ORN,and further the signal is relayed to the mushroom body(MB)and lateral horn(LH)by the projection neurons(PNs).Some proteins such as Dock,N-cadherin,and Fruitless play crucial roles in the physiology of Drosophila olfaction;loss of these proteins will lead to olfactory deficiencies.In this article we reviewed the major progress made in recent years.