In order to mine candidate vaccine antigens against ticks and to control ticks safely and effectively,the aim of this study was to immunize rabbits with purified aquaporins(AQPs)rD-mAQP1,rDmAQP2 and rDmAQP3 of Dermacentor marginatus.Blood collections for Western blot and ELISA tests were performed.The anti-tick challenge was conducted.The optimal expression conditions of rDmAQP1,rDmAQP2 and rDmAQP3 were screened by SDS-PAGE gel electrophore-sis.The three recombinant proteins were purified by HisSepNi-NTA6FF purification column.Rab-bits were divided into four groups of three rabbits each,including a control group and three immu-nized groups.The three purified recombinant proteins were separately immunized to three groups of rabbits,and the rabbits were immunized once on the 0th,14th and 21st day.Blood samples were collected every 7 days to prepare polyclonal antibodies.The reactivity was detected by Western blot and the antibody titer was detected by ELISA.Tick challenge test was carried out after the anti-body titer increased.The results showed that the optimal expression conditions for rDmAQP1 were induced for 8 h at IPTG concentration of 1.0 mmol/L and 37 ℃;the optimal expression conditions for rDmAQP2 were induced for 7 h at IPTG concentration of 1.0 mmol/L and 37 ℃;and the opti-mal expression conditions for rDmAQP3 were induced for 5 h at IPTG concentration of 1.0 mmol/L and 37 ℃.Western blot results showed that rDmAQP1,rDmAQP2 and rDmAQP3 all had certain reactivity.The ELISA results showed that the antibody titers of rabbits immunized with rD-mAQP1,rDmAQP2 and rDmAQP3 were as follows:the total anti-tick effect of rDmAQP1 protein was 79.74％,and the inhibition rates on average full-blooded tick weight,average egg weight and average egg hatching rate were 9.43％,25.17％and 63.81％,respectively.The total anti-tick effect of rDmAQP2 protein was 78.78％,and the inhibition rates of average full-blooded tick weight,av-erage egg weight and average egg hatching rate of Dermacentor marginatus were 8.30％,20.14％and 68.26％,respectively.The total anti-tick effect of rDmAQP3 protein was 87.91％,and the inhi-bition rates of average full-blooded tick weight,average egg weight and average egg hatching rate were 3.23％,22.47％and 80.5％,respectively.Through serological test and anti-tick test,it has been found that rDmAQP1,rDmAQP2 and rDmAQP3 all have the potential of candidate antigens against ticks,among which rDmAQP3 has the best immune effect,which lays a foundation for the study of the function of rDmAQP1,rDmAQP2 and rDmAQP3.

To predict the distribution and habitat of Dermacentor nuttallii in Xinjiang and to under-stand its life cycle history.In this study,Maximum Entropy Modeling(MaxEnt)was used to pre-dict the geographical distribution and adaptation area of Dermacentor nuttallii in Xinjiang,and jackknife test and response curve of environmental variables were used to evaluate the environmen-tal factors affecting the distribution of Dermacentor nuttallii.Dermacentor samples were collected randomly based on predicted sites.The species of Dermacentor was identified by the combination of morphological characteristics and molecular biology.The New Zealand white rabbit was the only blood donor,and the life cycle and biological characteristics of the tick were observed and recorded by the method of earmuffs feeding under natural light in the laboratory.The jackknife test and SPSS analysis results showed that the main environmental variables affecting the distribution of suitable areas of Dermacentor nuttallii were average temperature(Bio1),average daily tempera-ture range(Bio2),seasonal temperature change(Bio4),driest month precipitation(Bio14),precip-itation variation coefficient(Bio15).The response curves of major environmental variables showed that Dermacentor nuttallii had the highest presence probability when Bio1 was 15.58 ℃,Bio2 was 6.19 ℃,Bio4 had a coefficient of variation of 1 500,Bio14 had a coefficient of variation of 20 mm,Bio15 had a coefficient of variation of 23.799 and Bio19 was 69 mm.The prediction results showed that the suitable areas of Dermacentor nuttallii in Xinjiang were Tianshan Mountain range in Junggar Basin,Turpan basin in Altai Mountain valley and some areas south of Tianshan Mountain range,accounting for 50.99％of the total area of Xinjiang.Dermacentor were collected from the predicted area according to MaxEnt model and identified as Dermacentor nuttallii by morphologi-cal and molecular biological methods.The full blood stage was 5.31 d,the degeneration stage was 8.19 d,and the degeneration rate reached 95.5％.If the full blood stage was 8.65 d and the degener-ation stage was 12.86 d,the degeneration rate reached 98％.The full blood stage of adult ticks was 6.75 d,the early egg stage of full blood females was 5.86 d,and the spawning stage of full blood fe-males was 12.5 d.The eggs hatched into young ticks after 25.92 d,and the hatching rate reached 90％.Dermacentor nuttallii took 62-107 d to complete a life history,with an average of 86.06 d.The constructed MaxEnt model has high prediction accuracy and accuracy.According to the varia-ble analysis of the main environmental factors,precipitation and temperature are the main environ-mental factors affecting Dermacentor nuttallii.The study of the whole life cycle of Dermacentor nuttallii in Xinjiang provides the basis for establishing the method of artificial breeding of pure species of Dermacentor nuttallii in Xinjiang.