蚤亚科线粒体基因组研究进展

Research advances on Pulicinae mitochondrial genomes

蚤亚科(Pulicinae)隶属于蚤目(Siphonaptera)蚤总科(Pulicoidea)蚤科(Pulicidae),是啮齿动物和猫犬常见的嗜血性体外寄生虫。已测定的蚤亚科共3属5种(猫栉首蚤、犬栉首蚤、东洋栉首蚤、印鼠客蚤和人蚤),其线粒体基因组的结构特征和变异情况具有以下特点:线粒体基因组保留了节肢动物典型的排列模式,未发生基因缺失、增加和重排现象;AT含量较高,且AT-偏斜和GC-偏斜均为负值,与大多数全变态类昆虫一样,密码子使用度具有明显的偏好性;人蚤的丝氨酸转运RNA (trnS1)呈典型的三叶草结构,其余物种与后生动物一样trnS1缺失D-臂,且5种蚤亚科物种的trnS1以UCU为反密码子代替了常见的GCU;蚤亚科控制区偏大,最大可达7 kb以上,主要以二核苷酸重复为主,NADH脱氢酶亚基4 (nad4)~nad4L之间存在7 bp的保守重叠区,与多数全变态类昆虫一致。本文以期对今后蚤亚科在全变态类昆虫中的演化提供参考。

Pulicinae belongs to Siphonaptera, Pulicoidea, Pulicidae, are common haematophagous ectoparasites in rodents, cats and dogs. A total of 3 genera and 5 species(Ctenocephalides felis, C. canis, C. orientis, Xenopsylla cheopis and Pulex irritans) have been determined. The structural characteristics and polymorphisms of the mitogenome have the following characteristics: the mitogenome retains the typical arrangement of the arthropod ancestor without gene deletions, additions, or rearrangements;higher AT content and both AT-skewness and GC-skewness were negative.The preferred codon usage is similar to most holometabolous insects. The tRNA-Ser(trnS1) gene of P. irritans shows a typical cltornveSr1l eaf structure, and the other species have the same trnS1 but lacks the D-arm with the metazoan animals. The of 5 species within the Pulicinae subfamily replaced the common GCU with UCU as the anticodon.The control region of the Pulicinae subfamily is relatively large with up to more than 7 kb in length and are mainly dinucleotide repeats. Similar to most holometabolous insects, there is a 7 bp conserved overlapping region between NADH dehydrogenase subunit 4(nad4) and nad4L. This article aims to provide reference for the evolution of the flea subfamily in holometamorphosis insects in the future.