title: Genetic diversity of Trypanosoma cruzi in bats, and multilocus phylogenetic and phylogeographical analyses supporting Tcbat as an independent DTU (discrete typing unit).
abstract: Trypanosoma cruzi is a complex of phenotypically and genetically diverse isolates distributed in six discrete typing units (DTUs) designated as TcI-TcVI. Five years ago, T. cruzi isolates from Brazilian bats showing unique patterns of traditional ribosomal and spliced leader PCRs not clustering into any of the six DTUs were designated as the Tcbat genotype. In the present study, phylogenies inferred using SSU rRNA (small subunit of ribosomal rRNA), gGAPDH (glycosomal glyceraldehyde 3-phosphate dehydrogenase) and Cytb (cytochrome b) genes strongly supported Tcbat as a monophyletic lineage prevalent in Brazil, Panama and Colombia. Providing strong support for Tcbat, sequences from 37 of 47 nuclear and 12 mitochondrial genes (retrieved from a draft genome of Tcbat) and reference strains of all DTUs available in databanks corroborated Tcbat as an independent DTU. Consistent with previous studies, multilocus analysis of most nuclear genes corroborated the evolution of T. cruzi from bat trypanosomes its divergence into two main phylogenetic lineages: the basal TcII; and the lineage clustering TcIV, the clade comprising TcIII and the sister groups TcI-Tcbat. Most likely, the common ancestor of Tcbat and TcI was a bat trypanosome. However, the results of the present analysis did not support Tcbat as the ancestor of all DTUs. Despite the insights provided by reports of TcIII, TcIV and TcII in bats, including Amazonian bats harbouring TcII, further studies are necessary to understand the roles played by bats in the diversification of all DTUs. We also demonstrated that in addition to value as molecular markers for DTU assignment, Cytb, ITS rDNA and the spliced leader (SL) polymorphic sequences suggest spatially structured populations of Tcbat. Phylogenetic and phylogeographical analyses, multiple molecular markers specific to Tcbat, and the degrees of sequence divergence between Tcbat and the accepted DTUs strongly support the definitive classification of Tcbat as a new DTU.
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil. Electronic address: lulima@usp.br.
authors.forename: Luciana
authors.initials: L
authors.lastname: Lima
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil. Electronic address: oneidae07@usp.br.
authors.forename: Oneida
authors.initials: O
authors.lastname: Espinosa-Álvarez
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil. Electronic address: paolaortiz27@gmail.com.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Ortiz
authors.affiliation: Laboratorio de Investigaciones en Parasitología Tropical, Facultad de Ciencias, Universidad del Tolima, Ibagué, Colombia. Electronic address: jatrejovaron@gmail.com.
authors.forename: Javier A
authors.initials: JA
authors.lastname: Trejo-Varón
authors.affiliation: Laboratorio de Investigaciones en Parasitología Tropical, Facultad de Ciencias, Universidad del Tolima, Ibagué, Colombia. Electronic address: jcarranza@ut.edu.co.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Carranza
authors.affiliation: Division of Mammals, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA; Centro de Investigación en Enfermedades Infecciosas y Crónicas, Escuela de Biología, Pontificia Universidad Católica del Ecuador, Quito, Ecuador. Electronic address: mpinto@amnh.org.
authors.forename: C Miguel
authors.initials: CM
authors.lastname: Pinto
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Myrna G
authors.initials: MG
authors.lastname: Serrano
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA. Electronic address: gabuck@vcu.edu.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Buck
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil. Electronic address: erney@usp.br.
authors.forename: Erney P
authors.initials: EP
authors.lastname: Camargo
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil. Electronic address: mmgteix@icb.usp.br.
authors.forename: Marta M G
authors.initials: MM
authors.lastname: Teixeira
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001938:Brazil; D014355:Chagas Disease / Q000469:parasitology*; D002685:Chiroptera / Q000469:parasitology*; D003105:Colombia; D014644:Genetic Variation; D005838:Genotype; D058885:Multilocus Sequence Typing; D010176:Panama; D010802:Phylogeny; D058974:Phylogeography; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000302:isolation & purification*
keywords: Chiroptera; Evolution; Genotyping; Multilocus analysis; Phylogeny; Trypanosoma cruzi