1 2 Morphometric and molecular evidence of intraspecific biogeographical 3 differentiation of Rhodnius pallescens (HEMIPTERA: REDUVIIDAE: RHODNIINI) 4 from Colombia and Panama 5 Andrés Gómez-Palacio a,⇑ Q4 , Nicolás Jaramillo-Ocampo a , Harling Caro-Riaño a , Sebastián Diaz a , 6 Fernando A. Monteiro b , Ruben Pérez c , Francisco Panzera c , Omar Triana a 7 a Grupo de Biología y Control de Enfermedades Infecciosas – BCEI, Sede de Investigación Universitaria – SIU, Instituto de Biología, Universidad de Antioquia, Medellín, Colombia 8 b Laboratório de Genética Molecular e Microorganismos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil 9 c Sección de Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay 10 11 13 article info 14 Article history: 15 Received 7 December 2011 16 Received in revised form 27 March 2012 17 Accepted 5 April 2012 18 Available online xxxx 19 Keywords: 20 Triatominae 21 Rhodnius pallescens 22 Chagas Q3 disease 23 Cytochrome b 24 Morphometrics 25 Genome size 26 27 abstract 28 Rhodnius pallescens is considered the main vector of Chagas disease in Panama and a relevant secondary 29 vector in northern Colombia. Previous data reported that this species presents cytogenetically heteroge- 30 neous populations, which are probably biogeographically segregated. To provide new information on the 31 diversity of R. pallescens, we compared several populations from Colombia and Panama based on the mor- 32 phometric analyses of wings, mitochondrial cytochrome b (cyt b) gene sequencing, and genomic DNA 33 measurements. Although no differences in DNA amount were detected, significant differences in cyt b 34 sequences as well as wing size and shape were identified among populations. The results obtained in this 35 work indicate R. pallescens comprises two evolutionary lineages with genetic and morphological differ- 36 ences that could be explained by their geographic isolation in distinct ecological zones. These results 37 provide new insight into R. pallescens population diversity and the underlying biological processes that 38 shape its evolution. 39 Ó 2012 Published by Elsevier B.V. 40 41 42 1. Introduction 43 The subfamily Triatominae (Hemiptera–Reduviidae) includes 44 141 species of hematophagous insects taxonomically grouped into 45 five tribes and 15 genera (Jurberg et al., 2009; Schofield and 46 Galvão, 2009). Most species are potential vectors of the protozoan 47 parasite Trypanosoma cruzi, the causative agent of American try- 48 panosomiasis, or Chagas disease. In Central America, Rhodnius 49 pallescens is the only endemic Rhodnius species, because R. prolixus 50 is thought to have been accidentally introduced by humans 51 (Zeledón, 2004). R. pallescens is widely distributed across Central 52 America and Colombia (Galvão et al., 2003), where it occurs under 53 a wide range of climatic conditions and ecological zones (Gottden- 54 ker et al., 2011; Jaramillo et al., 2000). Although this species inhab- 55 its sylvatic palm trees, adult insects frequently invade human 56 dwellings, attracted by artificial light, a behavior that increases 57 its importance in disease transmission (Calzada et al., 2006; 58 Cantillo-Barraza et al., 2010; Gottdenker et al., 2011; Zeledón 59 et al., 2006). 60 Rhodnius pallescens is the main vector in Panama (Calzada et al., 61 2010, 2006) and is one secondary vector in Costa Rica, Nicaragua 62 (Zeledón et al., 2006), and the Colombian Caribbean region 63 (Cantillo-Barraza et al., 2010; Guhl et al., 2007), where R. prolixus 64 and T. dimidiata are the main vectors (Guhl, 2007). Therefore, this 65 species was included as an important target to be controlled in 66 the Central American Initiative for the interruption of vectorial 67 transmission (Ponce, 1999a,b). 68 An apparent epidemiological heterogeneity between Panamian 69 and Colombian R. pallescens populations seems to suggest a 70 possible biological differentiation between them. Thus, whereas 71 in Panama R. pallescens have often been found inside dwellings 72 infected with T. cruzi and therefore have been the principal Chagas 73 vector there (Calzada et al., 2010, 2006), in Colombia it is assumed 74 to be a sporadic vector related to accidental T. cruzi transmission to 75 humans and is therefore considered a secondary vector (Cantillo- 76 Barraza et al., 2010; Guhl et al., 2007). The variation in epidemio- 77 logical relevance in R. pallescens could result from several 78 endogenous factors such as vectorial capacities of biological or 79 evolutionary divergent entities (i.e., different populations’ struc- 80 ture could involve differentiation of certain niche attributes such 81 as bloodmeal sources or the ability to colonize artificial habitats, 82 etc.) as well as exogenous factors such as human activities (i.e., 1567-1348/$ - see front matter Ó 2012 Published by Elsevier B.V. http://dx.doi.org/10.1016/j.meegid.2012.04.003 ⇑ Corresponding author. Tel.: +57 4 2196681; fax: +57 4 2196520. E-mail address: amgomez@gmail.com (A. Gómez-Palacio). Infection, Genetics and Evolution xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Infection, Genetics and Evolution journal homepage: www.elsevier.com/locate/meegid MEEGID 1272 No. of Pages 10, Model 5G 2 June 2012 Please cite this article in press as: Gómez-Palacio, A., et al. Morphometric and molecular evidence of intraspecific biogeographical differentiation of Rhod- nius pallescens (HEMIPTERA: REDUVIIDAE: RHODNIINI) from Colombia and Panama. Infect. Genet. Evol. (2012), http://dx.doi.org/10.1016/ j.meegid.2012.04.003