Authors

L Hernandez⁶; M Paterno⁷; A G Villacís⁴; B Andersson¹; ²; J A Costales⁴; M De Noia⁵; S Ocaña-Mayorga⁴; C A Yumiseva⁴; M J Grijalva³; M S Llewellyn⁶;  ¹ Karolinska Institutet, Sweden;  ² Karolinska Institutet;  ³ Ohio University, United States;  ⁴ Pontifical Catholic University of Ecuador, Ecuador;  ⁵ Universität Bielefeld, Germany;  ⁶ University of Glasgow;  ⁷ University of Padua, Italy

Discussion

Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become a powerful tool for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b-RAD genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses. The 2b-RAD protocol was carried out in-house at a non-specialised laboratory using 20 R. ecuadoriensis adults collected from the Central coast and Southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analysed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphisms (SNPs) discovery. Preliminary genomic analyses (AMOVA, pairwise F_ST, principal components and coordinates and Bayesian clustering) were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However only BcgI and CspCI Restriction Enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses highlighted a strong signal of fine and coarse scale genetic structuring across the study area. Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at local, epidemiologically relevant, scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialised molecular biological equipment.