{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T15:01:24Z","timestamp":1785855684188,"version":"3.56.0"},"reference-count":54,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T00:00:00Z","timestamp":1777420800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      <jats:italic>Citellophilus tesquorum<\/jats:italic>\n                      is a major flea vector in natural plague foci across the Palaearctic region of China, representing a significant threat to veterinary and public health. Precise identification and sound taxonomic delimitation of its subspecies are critical for effective vector surveillance and evolutionary research.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      We first performed morphological identification to guarantee specimen authenticity and accuracy, then sequenced and annotated the complete mitochondrial genomes of\n                      <jats:italic>C. t. dzetysuensis<\/jats:italic>\n                      and\n                      <jats:italic>C. t. mongolicus<\/jats:italic>\n                      using the Illumina NovaSeq platform. Comparative mitogenomic and phylogenetic analyses were conducted with 33 publicly available flea mitochondrial genomes to explore genomic evolution, codon usage patterns, and phylogenetic relationships.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The two newly sequenced mitogenomes showed high structural conservation and a strong AT bias, consistent with typical features in Siphonaptera. Natural selection was identified as the dominant force driving codon usage bias. Phylogenetic reconstructions revealed that\n                      <jats:italic>C. t. dzetysuensis<\/jats:italic>\n                      clustered strongly with\n                      <jats:italic>C. t. sungaris<\/jats:italic>\n                      , while\n                      <jats:italic>C. t. mongolicus<\/jats:italic>\n                      formed a well-supported sister clade, indicating genetic divergence among these subspecies.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>The observed genetic differentiation is likely driven by long-term geographic isolation and host adaptation. This study establishes an integrative morphological and mitogenomic framework, enriches flea mitochondrial genomic resources, and provides key molecular evidence for the phylogeny, taxonomy, and surveillance of flea vectors.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fvets.2026.1785674","type":"journal-article","created":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T06:02:19Z","timestamp":1777442539000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Mitochondrial genomes of two subspecies of Citellophilus tesquorum: Insights into the molecular evolution and phylogenetic analysis within Siphonaptera"],"prefix":"10.3389","volume":"13","author":[{"given":"Mingna","family":"Duan","sequence":"first","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuran","family":"Xia","sequence":"additional","affiliation":[{"name":"Northwestern Polytech Univ, Sci & Technol Thermostructural Composite Mat Lab","place":["Xi'an, Shaanxi, China"]},{"name":"Northwestern Polytech Univ, Ningbo Inst, Ningbo","place":["Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dandan","family":"Jiang","sequence":"additional","affiliation":[{"name":"School of Public Health, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaobo","family":"Tang","sequence":"additional","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rui","family":"Hou","sequence":"additional","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lanling","family":"Tian","sequence":"additional","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tao","family":"Wang","sequence":"additional","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tianguang","family":"Ren","sequence":"additional","affiliation":[{"name":"School of Government Administration, Baoshan University","place":["Baoshan, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xing","family":"Yang","sequence":"additional","affiliation":[{"name":"Integrated Laboratory of Pathogenic Biology, College of Preclinical Medicine, Dali University","place":["Dali, Yunnan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,29]]},"reference":[{"key":"ref1","first-page":"756","volume-title":"Concepts in Animal Parasitology","author":"Lareschi","year":"2024"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.48580\/dfvll-48fy","article-title":"Lewis world species flea (Siphonaptera) list (version 2.0)","author":"Hastriter","year":"2024","journal-title":"Catalogue of Life"},{"key":"ref3","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/B978-0-12-814043-7.00010-8","volume-title":"Medical and Veterinary Entomology","author":"Durden","year":"2019"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"e667","DOI":"10.1016\/j.ijid.2009.11.011","article-title":"Fleas and flea-borne diseases","volume":"14","author":"Bitam","year":"2010","journal-title":"Int J Infect Dis"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"105627","DOI":"10.1016\/j.actatropica.2020.105627","article-title":"Fleas and flea-borne diseases of North Africa","volume":"211","author":"Hamzaoui","year":"2020","journal-title":"Acta Trop"},{"key":"ref6","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1007\/978-94-024-0890-4_5","volume-title":"Yersinia Pestis","author":"Dubyanskiy","year":"2016"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"565","DOI":"10.1134\/S0013873819050014","article-title":"Diversity of fleas (Siphonaptera), vectors of plague pathogens: the flea Citellophilus Tesquorum (Wagner, 1898), a parasite of ground squirrels of the genus Spermophilus","volume":"99","author":"Medvedev","year":"2019","journal-title":"Entmol Rev"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.3390\/insects13020126","article-title":"Genetic evidence of an isolation barrier between flea subspecies of Citellophilus Tesquorum (Wagner, 1898) (Siphonaptera: Ceratophyllidae)","volume":"13","author":"Ilinsky","year":"2022","journal-title":"Insects"},{"key":"ref9","volume-title":"Insect. Siphonaptera","author":"Wu","year":"2007"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"1553152","DOI":"10.3389\/fvets.2025.1553152","article-title":"Detection of spotted fever group Rickettsiae and Coxiella Burnetii in long-tailed ground squirrels (Spermophilus Undulatus) and their Ectoparasites","volume":"12","author":"Han","year":"2025","journal-title":"Front Vet Sci"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"634","DOI":"10.1186\/s13071-018-3233-6","article-title":"Diversity of Rickettsia species in border regions of northwestern China","volume":"11","author":"Song","year":"2018","journal-title":"Parasit Vectors"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"100958","DOI":"10.1016\/j.ijppaw.2024.100958","article-title":"Bartonella, Blechomonas and Trypanosoma in fleas from the long-tailed ground squirrel (Spermophilus Undulatus) in northwestern China","volume":"24","author":"Han","year":"2024","journal-title":"Int J Parasitol Parasites Wildl"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.3390\/insects13080707","article-title":"Morphometrics as a complementary tool in the differentiation of two cosmopolitan flea species: Ctenocephalides felis and Ctenocephalides canis","volume":"13","author":"Garc\u00eda-S\u00e1nchez","year":"2022","journal-title":"Insects"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"95","DOI":"10.1146\/annurev-ento-011613-162007","article-title":"Insect mitochondrial genomics: implications for evolution and phylogeny","volume":"59","author":"Cameron","year":"2014","journal-title":"Annu Rev Entomol"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"e0197524","DOI":"10.1371\/journal.pone.0197524","article-title":"Sequencing of complete mitochondrial genomes confirms Synonymization of Hyalomma asiaticum asiaticum and kozlovi, and advances phylogenetic hypotheses for the Ixodidae","volume":"13","author":"Liu","year":"2018","journal-title":"PLoS One"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"455","DOI":"10.1089\/cmb.2012.0021","article-title":"Spades: a new genome assembly algorithm and its applications to single-cell sequencing","volume":"19","author":"Bankevich","year":"2012","journal-title":"J Comput Biol"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"e112963","DOI":"10.1371\/journal.pone.0112963","article-title":"Pilon: an integrated tool for comprehensive microbial variant detection and genome assembly improvement","volume":"9","author":"Walker","year":"2014","journal-title":"PLoS One"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"313","DOI":"10.1016\/j.ympev.2012.08.023","article-title":"Mitos: improved de novo metazoan mitochondrial genome annotation","volume":"69","author":"Bernt","year":"2013","journal-title":"Mol Phylogenet Evol"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"537","DOI":"10.1093\/bioinformatics\/bti054","article-title":"Circular genome visualization and exploration using CGview","volume":"21","author":"Stothard","year":"2005","journal-title":"Bioinformatics"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"e87","DOI":"10.1002\/imt2.87","article-title":"Using phylosuite for molecular phylogeny and tree-based analyses","volume":"2","author":"Xiang","year":"2023","journal-title":"Imeta"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"353","DOI":"10.1007\/bf00186547","article-title":"Patterns of nucleotide composition at fourfold degenerate sites of animal mitochondrial genomes","volume":"41","author":"Perna","year":"1995","journal-title":"J Mol Evol"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"3299","DOI":"10.1093\/molbev\/msx248","article-title":"Dnasp 6: DNA sequence polymorphism analysis of large data sets","volume":"34","author":"Rozas","year":"2017","journal-title":"Mol Biol Evol"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"5125","DOI":"10.1093\/nar\/14.13.5125","article-title":"Codon usage in yeast: cluster analysis clearly differentiates highly and lowly expressed genes","volume":"14","author":"Sharp","year":"1986","journal-title":"Nucleic Acids Res"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1016\/0378-1119(90)90491-9","article-title":"The 'effective number of codons' used in a gene","volume":"87","author":"Wright","year":"1990","journal-title":"Gene"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"2653","DOI":"10.1073\/pnas.85.8.2653","article-title":"Directional mutation pressure and neutral molecular evolution","volume":"85","author":"Sueoka","year":"1988","journal-title":"Proc Natl Acad Sci USA"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1007\/bf00163236","article-title":"Intrastrand parity rules of DNA Base composition and usage biases of synonymous codons","volume":"40","author":"Sueoka","year":"1995","journal-title":"J Mol Evol"},{"key":"ref27","doi-asserted-by":"publisher","DOI":"10.3390\/genes15070887","article-title":"Patterns in genome-wide codon usage Bias in representative species of lycophytes and ferns","volume":"15","author":"Xu","year":"2024","journal-title":"Genes (Basel)"},{"key":"ref28","volume-title":"R: A Language and Environment for Statistical Computing","year":"2016"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"431","DOI":"10.1093\/jhered\/esx033","article-title":"DAMBE6: new tools for microbial genomics, Phylogenetics, and molecular evolution","volume":"108","author":"Xia","year":"2017","journal-title":"J Hered"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"772","DOI":"10.1093\/molbev\/mst010","article-title":"MAFFT multiple sequence alignment software version 7: improvements in performance and usability","volume":"30","author":"Katoh","year":"2013","journal-title":"Mol Biol Evol"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"564","DOI":"10.1080\/10635150701472164","article-title":"Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments","volume":"56","author":"Talavera","year":"2007","journal-title":"Syst Biol"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"587","DOI":"10.1038\/nmeth.4285","article-title":"Modelfinder: fast model selection for accurate phylogenetic estimates","volume":"14","author":"Kalyaanamoorthy","year":"2017","journal-title":"Nat Methods"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"539","DOI":"10.1093\/sysbio\/sys029","article-title":"MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space","volume":"61","author":"Ronquist","year":"2012","journal-title":"Syst Biol"},{"key":"ref34","doi-asserted-by":"publisher","first-page":"1530","DOI":"10.1093\/molbev\/msaa015","article-title":"IQ-TREE 2: new models and efficient methods for phylogenetic inference in the genomic era","volume":"37","author":"Minh","year":"2020","journal-title":"Mol Biol Evol"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"W78","DOI":"10.1093\/nar\/gkae268","article-title":"Interactive tree of life (iTOL) V6: recent updates to the phylogenetic tree display and annotation tool","volume":"52","author":"Letunic","year":"2024","journal-title":"Nucleic Acids Res"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1016\/s0074-7696(08)62066-5","article-title":"Animal mitochondrial DNA: structure and evolution","volume":"141","author":"Wolstenholme","year":"1992","journal-title":"Int Rev Cytol"},{"key":"ref37","doi-asserted-by":"publisher","first-page":"252","DOI":"10.1007\/BF02099755","article-title":"The mitochondrial DNA molecular of Drosophila Yakuba: nucleotide sequence, Gene Organization, and genetic code","volume":"22","author":"Clary","year":"1985","journal-title":"J Mol Evol"},{"key":"ref38","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1080\/10635150590947843","article-title":"Evidence for multiple reversals of asymmetric mutational constraints during the evolution of the mitochondrial genome of Metazoa, and consequences for phylogenetic inferences","volume":"54","author":"Hassanin","year":"2005","journal-title":"Syst Biol"},{"key":"ref39","doi-asserted-by":"publisher","first-page":"5378","DOI":"10.1093\/nar\/22.24.5378","article-title":"Higher-order structure of bovine mitochondrial Trna(Seruga): chemical modification and computer modeling","volume":"22","author":"Watanabe","year":"1994","journal-title":"Nucleic Acids Res"},{"key":"ref40","doi-asserted-by":"publisher","first-page":"7666","DOI":"10.1038\/s41598-017-07977-0","article-title":"Complete mitochondrial genomes of Anopheles stephensi and An. dirus and comparative evolutionary mitochondriomics of 50 mosquitoes","volume":"7","author":"Hao","year":"2017","journal-title":"Sci Rep"},{"key":"ref41","doi-asserted-by":"publisher","DOI":"10.3390\/ani12202854","article-title":"First description of the mitogenome features of neofoleyellides genus (Nematoda: Onchocercidae) isolated from a wild bird (Pyrrhocorax Pyrrhocorax)","volume":"12","author":"Wu","year":"2022","journal-title":"Animals (Basel)"},{"key":"ref42","doi-asserted-by":"publisher","first-page":"677","DOI":"10.1111\/j.1096-0031.2008.00211.x","article-title":"A molecular phylogeny of fleas (Insecta: Siphonaptera): origins and host associations","volume":"24","author":"Whiting","year":"2008","journal-title":"Cladistics"},{"key":"ref43","doi-asserted-by":"publisher","first-page":"28316","DOI":"10.1038\/s41598-024-79492-y","article-title":"Taxonomy and phylogeny of rodents parasitic fleas in southeastern China with description of a new subspecies of Ctenophthalmus breviprojiciens","volume":"14","author":"Zhou","year":"2024","journal-title":"Sci Rep"},{"key":"ref44","doi-asserted-by":"publisher","first-page":"253","DOI":"10.1186\/s13071-024-06329-y","article-title":"The complete mitochondrial genome of the rodent flea Nosopsyllus laeviceps: genome description, comparative analysis, and phylogenetic implications","volume":"17","author":"Fu","year":"2024","journal-title":"Parasit Vectors"},{"key":"ref45","doi-asserted-by":"publisher","first-page":"31555","DOI":"10.1038\/s41598-024-84175-9","article-title":"The complete mitochondrial genome and phylogenetic implications of Paradoxopsyllus custodis and Stenischia montanis yunlongensis","volume":"14","author":"Chen","year":"2024","journal-title":"Sci Rep"},{"key":"ref46","doi-asserted-by":"publisher","first-page":"1558328","DOI":"10.3389\/fvets.2025.1558328","article-title":"The complete mitochondrial genomes of Macrostylophora euteles and Citellophilus tesquorum sungaris and the phylogenetics of known Siphonaptera mitogenomes","volume":"12","author":"Duan","year":"2025","journal-title":"Front Vet Sci"},{"key":"ref47","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1007\/s11686-025-01051-w","article-title":"The evolution of the order siphonaptera inferred from the first mitogenome of the family pygiopsyllidae","volume":"70","author":"Lin","year":"2025","journal-title":"Acta Parasitol"},{"key":"ref48","doi-asserted-by":"publisher","first-page":"1255017","DOI":"10.3389\/fvets.2023.1255017","article-title":"Complete mitochondrial genome of Ctenophthalmus quadratus and Stenischia humilis in China provides insights into fleas phylogeny","volume":"10","author":"Chen","year":"2023","journal-title":"Front Vet Sci"},{"key":"ref49","doi-asserted-by":"publisher","first-page":"1250381","DOI":"10.3389\/fvets.2023.1250381","article-title":"Analysis of complete mitogenomes and phylogenetic relationships of Frontopsylla spadix and Neopsylla specialis","volume":"10","author":"Liu","year":"2023","journal-title":"Front Vet Sci"},{"key":"ref50","doi-asserted-by":"publisher","first-page":"1218488","DOI":"10.3389\/fvets.2023.1218488","article-title":"Complete Mitogenomes characterization and phylogenetic analyses of Ceratophyllus anisus and Leptopsylla segnis","volume":"10","author":"Liu","year":"2023","journal-title":"Front Vet Sci"},{"key":"ref51","doi-asserted-by":"publisher","first-page":"18179","DOI":"10.1038\/s41598-024-69203-y","article-title":"The first mitogenome of the subfamily stenoponiinae (siphonaptera: ctenophthalmidae) and implications for its phylogenetic position","volume":"14","author":"Lin","year":"2024","journal-title":"Sci Rep"},{"key":"ref52","doi-asserted-by":"publisher","first-page":"1397","DOI":"10.1017\/s0031182024001604","article-title":"The first mitogenome of the genus amphalius (siphonaptera: ceratophyllidae) and its phylogenetic implications - corrigendum","volume":"151","author":"Pu","year":"2024","journal-title":"Parasitology"},{"key":"ref53","doi-asserted-by":"publisher","first-page":"100286","DOI":"10.1016\/j.crpvbd.2025.100286","article-title":"Molecular characterization of the oriental cat flea, Ctenocephalides orientis, parasitizing goats based on nuclear and mitochondrial protein-coding genes","volume":"8","author":"Ghauri","year":"2025","journal-title":"Curr Res Parasitol Vector Borne Dis"},{"key":"ref54","doi-asserted-by":"publisher","first-page":"e71108","DOI":"10.1002\/ece3.71108","article-title":"Evolution of the Neopsylla hongyangensis mitogenome: insights into the mitogenomic evolution of the orders siphonaptera and the phthiraptera","volume":"15","author":"Lin","year":"2025","journal-title":"Ecology and evolution"}],"container-title":["Frontiers in Veterinary Science"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1785674\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T06:02:22Z","timestamp":1777442542000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1785674\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,29]]},"references-count":54,"alternative-id":["10.3389\/fvets.2026.1785674"],"URL":"https:\/\/doi.org\/10.3389\/fvets.2026.1785674","relation":{},"ISSN":["2297-1769"],"issn-type":[{"value":"2297-1769","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,29]]},"article-number":"1785674"}}