方形黄鼠蚤(Citellophilus tesquorum)二亚种rDNA ITS1、ITS2序列的测定与分析

Sequence Analysis of ITS1 and ITS2 in rDNA of Two Subspecies of Citellophilus tesquorum

目的:从分子水平探讨方形黄鼠蚤七河亚种(Citellophilus tesquorum dzetysuensis)和阿尔泰亚种(C.t.altaicus)的分类地位。方法:用苯酚-氯仿法抽提单蚤胸段DNA,PCR扩增获得二亚种核糖体RNA基因(rD-NA)的两段内转录间隔序列(Internal Transcribed Spacer)ITS1和ITS2,分析比对序列差异。结果:阿尔泰亚种ITS1序列长1458bp,第508、783和1197位存在碱基差异;七河亚种ITS1序列长1452bp,亚种内无差异;两亚种间ITS1序列存在碱基差异,分别位于第508位(颠换A→C)和第783位(转换C→T),七河亚种从第1344到1349位缺失6bp,两亚种ITS2序列均长317bp,亚种内、亚种间均无差异。结论:七河亚种可能独立于阿尔泰亚种。

Objective：To study classification positions of Citellophilus tesquorum altaicus Ioff,1936 and Citellophilus tesquorum dzetysuensis Mikulin,1951 at molecular level. Methods：Genomic DNA from the thorax of single flea was isolated with Phenol-Chloroform method. Sequences of ITS1 and ITS2 in rDNA of the two subspecies were amplified with PCR. An analysis was made on the results. Results：The ITS1 sequence of C. t. altaicus was 1 458 bp,in which three base differences happened at the positions 508,783 and 1 197 at intra-subspecific level. The ITS1 sequence of C. t. dzetysuensis was 1 452 bp,in which no difference presented at intra-subspecific level. Two base substitutions at inter-subspecific level appeared at positions 508 （transversion,A→C） and 783 （transition,C→T）. C. t.dzetysuensis lacked 6 bp from the position 1 344 to 1 349. ITS2 sequences in both subspecies were 317 bp with no difference at neither intra-subspecific nor inter-subspecific level. Conclusion：The results may support that C.t. dzetysuensis is a subspecies independent from subspecies C. t. altaicus.