Abstract: 【Objective】To reveal the expression patterns of the chemosensory protein gene OasiCSP4 of Oedaleus asiaticus during phase transition,laying a foundation for the research of OasiCSP4 gene function.【Methods】The male and female O. asiaticus were dissected into eight tissues,including head,thorax,abdomen,wing,antennae,forelegs,midlegs and hindlegs in the 0,1,6,12,24 and 72 h of the isolation of gregarious and the crowding of solitary. qRT-PCR technology was used to determine the expression patterns and expression trend of OasiCSP4 in male and female O. asiaticus at different times and in different tissues.【Results】In the isolation of gregarious O. asiaticus,the relative expression level of OasiCSP4 of male forelegs was significantly higher than that of other tissues（P<0.05）.Treatment for 0,6,24,72 h,the relative expression level of OasiCSP4 of female forelegs were also significantly higher than that of other tissues（P<0.05）. Treatment for 1 h,the relative expression level of OasiCSP4 of female head was the highest. Treatment for 12 h,the relative expression level of OasiCSP4 in the female midlegs were also significantly higher than that of other tissues（P<0.05）. The relative expression level of OasiCSP4 in male head,antennae and midlegs decreased with the prolongation of treatment time. Treatment for 6 h,the relative expression level of OasiCSP4 in male wing,forelegs and female head,wing,antennae and forelegs were the highest. During the crowding of solitary,the relative expression level of OasiCSP4 in the foreleg of female showed significant differences compared to other tissues （P<0.05）. Except for the high expression of OasiCSP4 in male midlegs at 0,1,and 72 hours of treatment,it was highly expressed in male forelegs at all other treatment times.The relative expression levels of OasiCSP4 in male heads,wings,and female and male antennae,forelegs decreased with prolonged treatment time,with the highest relative expression levels observed in female heads and midlegs after 6 hours of treatment.【Conclusion】Chemosensory protein gene OasiCSP4 was differentially expressed during the phase transition in O. asiaticus.

Key words: Oedaleus asiaticus, Chemosensory protein gene, Expression profile, Phase transition