The fruit fly,Drosophila melanogaster,is able to discriminate visual landmarks and form visual long-term memory in a flight simulator.Studies focused on the molecular mechanism of long-term memory have shown that memory formation requires mRNA transcription and protein synthesis.However,little is known about the molecular mechanisms underlying the visual learning paradigm.The present study demonstrated that both spaced training procedure(STP)and consecutive training procedure(CTP)would induce long-term memory at 12 hour after training,and STP caused significantly higher 12-h memory scores compared with CTP.Labelfree quantification of liquid chromatography-tandem mass spectrometry(LC-MS/MS)and microarray were utilized to analyze proteomic and transcriptomic differences between the STP and CTP groups.Proteomic analysis revealed 30 up-regulated and 27 down-regulated proteins;Transcriptomic analysis revealed 145 up-regulated and 129 down-regulated genes.Among them,five candidate genes were verified by quantitative PCR,which revealed results similar to microarray.These results provide insight into the molecular components influencing visual long-term memory and facilitate further studies on the roles of identified genes in memory formation.
Drosophila melanogaster feeds mainly on rotten fruits, which contain many kinds of sugar. Thus, the sense of sweet taste has evolved to serve as a dominant regulator and driver of feeding behavior. Although several sugar receptors have been described, it remains poorly understood how the sensory input is transformed into an appetitive behavior. Here, we used a neural silencing approach to screen brain circuits, and identified neurons labeled by three Gal4 lines that modulate Drosophila feeding behavior. These three Gal4 lines labeled neurons mainly in the suboesophageal ganglia （SOG）, which is considered to be the fly＇s pri- mary taste center. When we blocked the activity of these neurons, flies decreased their sugar consumption significantly. In contrast, activation of these neurons resulted in enhanced feeding behavior and increased food consumption not only towards sugar, but to an array of food sources. Moreover, upon neuronal activation, the flies demonstrated feeding behavior even in the absence of food, which suggests that neuronal activation can replace food as a stimulus for feeding behavior. These findings indicate that these Gal4-1abeled neurons, which function downstream of sensory neurons and regulate feeding behavior to- wards different food sources is necessary in Drosophila feeding control.
SUN FeiWANG YiJinZHOU YanQiongVAN SWINDEREN BrunoGONG ZheFengLIU Li
