Investigating The Molecular Mechanism Of Circadian Clock Gene DEC2 In Sleep Regulation

Sleep,as an important biological process,which occupies about one third of our life,has great influence on our physical and mental health.With the increase of stress in modern society,more and more people exhibt sleep disruptions.Therefore,more and more people begin to be concerned about sleep,the need for thorough research to reveal the regulatory mechanism of sleep is becoming eminent.Previous study has reported that mutation in clock gene DEC2?DEC2-P384R?is associated with about 2 hour-sleep reduction in human,and transgenic mice carrying hDEC2-P384R compared with the mice carrying hDEC2-WT show increased activity and reduced sleep.Futher research found that flies expressing mDEC2-P384R in the mushroom body,a known sleep center in the fly brain,can also reduce sleep.Our preliminary work show that a series of sleep related genes have altered mRNA levels in mice carrying hDEC2-P384R.We also found that male expressing hDEC2-P384R in the mushroom body exhibit reduced sleep phonotype in constant darkness?DD?condition.To explore the molecular mechanism of DEC2 in sleep regulation,we choose fruit fly as our model.Based on our preliminary work,a series of sleep related genes have demonstrated changes in transcript level in hDEC2-P384R transgenic mice,we used real-time quantitative RT-PCR?qRT-PCR?to test whether the homologues of those genes are affected by DEC2-P384R mutation in flies.We found ten genes showing significant changes in mRNA levels in hDEC2-P384R transgenic flies.Among them,Clock,se,VGlut,ND-20,AP1?,5-HT7 exhibit alterations in the same direction as that observed in the mice,whereas CG32164,Gsts1,Erk7,Tbh show changes in the opposite direction.Next we utilized se¹,AP1?⁵H2064H2064 and Tbh^NP0208 mutant flies as well as Tbh RNAi and VGlut RNAi flies.We then tested whether these genes interact with DEC2-P384R to regulate sleep.The results are as follow:?1?se,AP1?,VGlut and Tbh genes may interact with DEC2-P384R genetically to regulate sleep;?2?se¹ mutation can affect sleep;?3?AP1?^5H2064 mutation can increase sleep.In conclusion,this study found four genes that may interact with DEC2-P384R genetically to affect sleep.They are se,AP1?,VGlut and Tbh.Moreover,we found two new genes that affect sleep in the fly,which are se and AP1?.These results open a new direction for characterizing how DEC2 regulates sleep and revealing new mechanism underlying sleep.