The complete mitochondrial genome sequences of the cat flea Ctenocephalides felis felis (Siphonaptera: Pulicidae) support the hypothesis that C. felis isolates from China and USA were the same C. f. felis subspecies.

ABSTRACT

The cat flea Ctenocephalides felis (Siphonaptera Pulicidae) is the most important ectoparasite in cats and dogs worldwide. Over the years, there has been much dispute regarding the taxonomic and systematic status of C. felis. Mitochondrial (mt) genome sequences are useful genetic markers for the identification and differentiation of ectoparasites, but the mt genome of C. felis and its subspecies has not yet been entirely characterized. In the present study, the entire mt genome of C. f. felis from China was sequenced and compared with that of C. felis from the USA. Both contain 37 genes and a long non-coding region of >6 kbp. The molecular identity between the Chinese and American isolates was 99%, except for the non-coding region. The protein-coding genes showed differences at both the nucleotide (1.2%) and amino acid (1%) levels. Interestingly, the cox1 gene of the Chinese isolate had an unusual putative start codon (TTT). Taken together, our analyses strongly support the hypothesis that C. felis isolates from China and the USA were the same C. f. felis subspecies. The mt genome sequence of the C. f. felis China isolate presented in this study provides useful molecular markers to further address the taxonomy and systematics of C. felis.