Zhan Y J, Zhang L X, Sun M T, Li X M, Wang Y, Li M Z, Tao D D, Sun E T
Department of Hygiene Inspection and Quarantine, Wannan Medical College, Wuhu 241002, China.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2020 Nov 25;33(1):66-70. doi: 10.16250/j.32.1374.2020154.
To analyze the sequences of mitochondrial cytochrome C oxidase subunit I gene () and 18S ribosomal RNA gene (), so as to identify the feasible DNA barcodes for 4 species of cheyletid mites and improve the DNA barcoding database for cheyletid mites.
Cheyletid mite samples were collected from small-scale flour mills in Fuyang, Wuhu and Tongling cities of Anhui Province from May 2018 to July 2019, extracted and morphologically identified. Then, genomic DNA was extracted from a single cheyletid mite, and the and gene sequences were obtained by PCR amplification, cloning and sequencing. The obtained sequences were aligned using the BLAST software. Multiple sequence alignment was done using the software ClustalX version 1.83 using the known gene sequences from cheyletid mites. The genetic distance was calculated using the software MEGA X, and the phylogenetic tree was created using the maximum likelihood method.
The DNA barcoding results of , and were consistent with the morphological identification, while no sequences pertaining to were retrieved in the GenBank database. The proportions of A + T were 69.6% and 55.1% in the and sequences of 4 cheyletid mites species, respectively, and the numbers of base substitutions were 137 and 46, respectively. There were 154 to 321 and 58 to 99 inter-species variation loci in the and gene sequences of 4 cheyletid mites species, respectively, and the intra-species genetic distance was all 0.020 or less in the and gene sequences of 4 cheyletid mites species, with inter-species genetic distance of 0.235 to 0.583 and 0.078 to 0.114, respectively. Phylogenetic analysis based on and genes showed that all four species of cheyletid mites were clustered into a branch with a 100% supportive rate, which was consistent with the morphological identification.
Mitochondrial gene is superior to gene as DNA barcodes for 4 species of cheyletid mites, which is more suitable to be used to investigate the phylogenetic relationship of at genus and species levels.
分析线粒体细胞色素C氧化酶亚基I基因（）和18S核糖体RNA基因（）序列，以确定4种肉食螨可行的DNA条形码，完善肉食螨DNA条形码数据库。
2018年5月至2019年7月从安徽省阜阳市、芜湖市和铜陵市的小型面粉厂采集肉食螨样本，进行提取和形态学鉴定。然后，从单头肉食螨中提取基因组DNA，通过PCR扩增、克隆和测序获得和基因序列。使用BLAST软件对所得序列进行比对。利用ClustalX 1.83软件，参照肉食螨已知基因序列进行多序列比对。使用MEGA X软件计算遗传距离，采用最大似然法构建系统发育树。
、和的DNA条形码结果与形态学鉴定结果一致，而在GenBank数据库中未检索到与相关的序列。4种肉食螨的和序列中A+T的比例分别为69.6%和55.1%，碱基替换数分别为137和46。4种肉食螨的和基因序列种间变异位点分别有154至321个和58至99个，4种肉食螨的和基因序列种内遗传距离均为0.020或更小，种间遗传距离分别为0.235至0.583和0.078至0.114。基于和基因的系统发育分析表明，4种肉食螨均聚为一个分支，支持率为100%，与形态学鉴定结果一致。
线粒体基因作为4种肉食螨的DNA条形码优于基因，更适合用于研究属和种水平的系统发育关系。
