新疆尉犁县某养殖场塔里木马鹿体表蜱和游离蜱的种类鉴定及分子遗传特征

目的] 了解塔里木马鹿体表蜱及其圈舍环境游离蜱种类及分子遗传特征。方法] 收集新疆尉犁县某规模化养殖场塔里木马鹿体表寄生和圈舍游离蜱共69只,使用体视显微镜对其进行形态学观察和种类初步鉴定;基于蜱线粒体SSU rRNA基因位点和COX I基因位点对其DNA进行PCR扩增,通过序列比对数据鉴定其种类,利用生物信息学方法解析其分子遗传特征。结果] 经形态学观察,鉴定69只蜱均属璃眼蜱属,雌蜱和雄蜱分别有37只和32只。基于SSU rRNA基因位点,对成功获得的63只蜱序列进行比对,鉴定出18只为残缘璃眼蜱,均为同一序列型,命名为SCtype1（n=18）;45只为亚洲璃眼蜱,具有4种序列型,分别命名为SYtype1（n=3）、SYtype2（n=40）、SYtype3（n=1）和SYtype4（n=1）。基于COX I基因位点,对成功获得的64只蜱序列进行对比,鉴定出24只为残缘璃眼蜱,具有2种序列型,分别命名为CCtype1（n=22）和CCtype2（n=2）;40只为亚洲璃眼蜱,具有5种序列型,分别命名为CYtype1（n=25）、CYtype2（n=7）、CYtype3（n=4）、CYtype4（n=3）和CYtype5（n=1）。种系进化分析显示,在SSU rRNA基因位点,亚洲璃眼蜱序列单独形成一个亚群分支,与其他璃眼蜱属蜱的序列形成一个大的亚群分支;在COX I基因位点,亚洲璃眼蜱序列和残缘璃眼蜱序列单独形成一个亚群分支,与其他属蜱的序列形成不同的亚群分支。结论] 新疆尉犁县塔里木马鹿体表蜱与游离蜱种类为亚洲璃眼蜱和残缘璃眼蜱。研究结果为鹿科动物寄生蜱的种类分布调查和遗传进化特征分析提供了基础数据。

Species Identification and Molecular Genetic Characteristics of Ticks on Body Surface and in Habitat of Tarim Red Deer （Cervus canadensis） from a Farm in Yuli County of Xinjiang,China

Objective] The present study was conducted to understand the species and molecular genetic characteristics of ticks on body surface and in habitat of Tarim red deer （Cervus canadensis）. Method] A total of 69 ticks were collected from body surface and habitat of Tarim red deer in a large scale farm in Yuli County of Xinjiang, China. Morphological observation and preliminary species identification were performed by stereomicroscope. PCR assays targeting on mitochondrial SSU rRNA gene and COX I gene were performed. The species of the obtained ticks was identified by sequence alignment of the two genes, and their molecular characteristics were analyzed by bioinformatics method. Result] Morphological observation showed that all of the 69 ticks, including 37 females and 32 males, were identified as belonging to the genus Hyalomma. The SSU rRNA gene sequence of 63 ticks was successfully obtained. Based on the sequence alignment of SSU rRNA gene, 18 ticks were identified as Hyalomma detritum （H. detritum） , and all of them were the same sequence type designated as SCtype1 （n=18）; 45 ticks were identified as Hyalomma asiaticum （H. asiaticum） with 4 sequence types designated as SYtype1 （n=3）, SYtype2 （n=40）, SYtype3 （n=1） and SYtype4 （n=1）, respectively. The COX I gene sequence of 64 ticks was successfully obtained. Based on the sequence alignment of COX I gene, 24 ticks were identified as H. detritum with 2 sequence types designated as CCtype1 （n=22） and CCtype2 （n=2）, respectively; 40 ticks were identified as H. asiaticum with 5 sequence types designated as CYtype1 （n=25）, CYtype2 （n=7）, CYtype3 （n=4）, CYtype4 （n=3） and CYtype5 （n=1）, respectively. Phylogenetic analysis showed that at SSU rRNA gene, the sequences of H. asiaticum formed an individual subgroup branch, and formed a large subgroup branch with those of other Hyalomma species; at COX I gene, the sequences of H. detritum and H. asiaticum formed an individual subgroup branch, while belonged to different subgroup branches with those of other genus in the family Ixodoidea. Conclusion] The species of the ticks collected from body surface and habitat of Tarim red deer in Yuli County are H. asiaticum and H. detritum. Our results provide basic data for species distribution investigation and genetic evolution characterization of parasitic ticks in Cervidae animals.