Front Vet Sci. 2026 Jun 23;13:1865746. doi: 10.3389/fvets.2026.1865746. eCollection 2026.
ABSTRACT
Fleas are common blood-sucking external parasites found on mammals; they serve as important vectors for various pathogenic microorganisms and pose a serious threat to human and animal health. Mitochondrial genomes have been widely used in studies such as DNA barcoding for species identification and phylogenetics. Therefore, in this study, we performed sequencing of Neopsylla specialis dechingensis and Neopsylla stevensi sichuanyunnana on the Illumina NovaSeq platform. Genome assembly and gene annotation were subsequently done to obtain their complete mitochondrial genomes. Besides the two newly sequenced specimens, sequence information of 35 extra flea taxa downloaded from the NCBI database was adopted for overall comparative evaluation. The results showed that a significant AT base bias was present in the mitochondrial sequences of all 37 flea species tested. The Ka/Ks values calculated for the 13 PCGs were all lower than 1, which indicates that these genes are subject to persistent purifying selection. The Pi values indicated that ATP8 exhibited the highest variability, while ND5 was the most conserved. Phylogenetic trees were built based on 13 PCGs of 37 species, with Boreus elegans assigned as the outgroup, and both trees share highly identical topological structures. Both N. s. dechingensis and N. s. sichuanyunnana were clustered within the family Ctenophthalmidae. Furthermore, both trees supported the monophyly of the family Pulicidae with auto-expanded support values and posterior probabilities of 100 and 1, respectively. As important disease vectors, fleas pose a substantial risk to both human and veterinary health. However, complete mitochondrial genome data for fleas are currently extremely limited. For this reason, ongoing expansion of the flea mitochondrial genome database is critical to advancing related research efforts.
PMID:42416297 | PMC:PMC13339032 | DOI:10.3389/fvets.2026.1865746