title: Dinotefuran-induced morphophysiological changes in semi-engorged females Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) ticks: Ultra-structural evaluation.
abstract: The present study demonstrated the effects of dinotefuran (active ingredient of the acaricide Protetor Pet®) on the ovary and midgut cells of semi engorged R. sanguineus females exposed to different concentrations of this chemical. For this, 120 semi-engorged females were divided into four treatment groups with 30 individuals each: group I or control (distilled water), group II (5000ppm), groups III (6250ppm) and group IV (8334ppm of dinotefuran). All the ticks were immersed in the different concentrations of dinotefuran or in distilled water for 5min and then dried and kept in BOD incubator for 7days. The results showed alterations mainly regarding the damaged cell structures, such as yolk granules, organelles and the plasma membrane of the germ cells. In addition, structures related with defense mechanisms were found, such as vacuoles, cytoskeletal filaments, and myelin figures in the germ cells. Damages in the generative cells of the midgut, alterations in the size of digestive cells, the number of endosomes, digestive vacuoles, digestive residues, lipid drops and organelles in the cytoplasm of the digestive cells and the presence of microvilli in the plasma membrane of these cells also demonstrate the progressive damages caused by the action of dinotefuran in the midgut and germ cells of R. sanguineus semi-engorged females. The concentrations applied partially impaired the digestive processes; and, without proper nutrition, all the ectoparasite's physiologic events are prevented from occurring, leading the individual to death. The germ cells were also damaged, and probably would not be able to advance in their development (I-V) and complete the vitellogenesis, which would affect the fertility of the female and consequently impede the formation of a new individual.
authors.affiliation: Department of Biology, Institute of Biosciences, São Paulo State University-UNESP, Av. 24A, n° 1515, Postal Code 199, Zip Code: 13506-900, Rio Claro, SP, Brazil. Electronic address: patyrosaoliv@yahoo.com.br.
authors.forename: Patrícia Rosa
authors.initials: PR
authors.lastname: de Oliveira
authors.affiliation: Department of Biology, Institute of Biosciences, São Paulo State University-UNESP, Av. 24A, n° 1515, Postal Code 199, Zip Code: 13506-900, Rio Claro, SP, Brazil.
authors.forename: Luis Adriano
authors.initials: LA
authors.lastname: Anholeto
authors.affiliation: Department of Animal Pathology, Faculty of Agronomic and Veterinary Sciences, São Paulo State University-UNESP, Via de Acesso Prof. Paulo Castellane, s/n, Zip Code: 14884-900, Jaboticabal, SP, Brazil; Graduate Program in Animal Science, School of Agricultural Science and Veterinary Medicine, The Pontificia Universidade Catolica do Parana - PUCPR, Rua Imaculada Conceição, 1155, Zip Code 80215-901 Curitiba, PR, Brazil.
authors.forename: Gerváso Henrique
authors.initials: GH
authors.lastname: Bechara
authors.affiliation: Department of Biology, Institute of Biosciences, São Paulo State University-UNESP, Av. 24A, n° 1515, Postal Code 199, Zip Code: 13506-900, Rio Claro, SP, Brazil.
authors.forename: Maria Izabel
authors.initials: MI
authors.lastname: Camargo Mathias
mesh_terms: D056810:Acaricides / Q000494:pharmacology*; D000818:Animals; D003593:Cytoplasm / Q000187:drug effects / Q000648:ultrastructure; D004064:Digestive System / Q000187:drug effects* / Q000648:ultrastructure; D004530:Egg Yolk / Q000187:drug effects / Q000648:ultrastructure; D000066473:Embryonic Germ Cells / Q000187:drug effects / Q000648:ultrastructure; D005260:Female; D005298:Fertility / Q000187:drug effects; D006146:Guanidines / Q000494:pharmacology*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology*; D015388:Organelles / Q000187:drug effects / Q000648:ultrastructure; D010053:Ovary / Q000187:drug effects* / Q000648:ultrastructure; D048508:Rhipicephalus sanguineus / Q000187:drug effects / Q000648:ultrastructure*; D014818:Vitellogenesis / Q000187:drug effects
chemical_list: D056810:Acaricides; D006146:Guanidines; D000073943:Neonicotinoids; D009574:Nitro Compounds; C465368:dinotefuran
keywords: Acaricide; Control; Dinotefuran; Rhipicephalus sanguineus; Ultrastructure