title: Neuropeptidomics in Triatoma infestans. Comparative transcriptomic analysis among triatomines.
abstract: Chagas' disease, affecting up to 6-7 million people worldwide, is transmitted to humans through the feces of triatomine kissing bugs. From these, Rhodnius prolixus, Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis are important vectors distributed throughout the Latin American subcontinent. Resistance to pyrethroids has been developed by some triatomine populations, especially T. infestans, obstructing their control. Given their role in the regulation of physiological processes, neuroendocrine-derived factors have been proposed as a source of molecular targets for new-generation insecticides. However, the involvement of neuropeptides in insecticide metabolism and resistance in insects has been poorly studied. In the present work, the sequences of 20 neuropeptide precursor genes in T. infestans, 16 in T. dimidiata, and 13 in T. pallidipennis detected in transcriptomic databases are reported, and a comparative analysis in triatomines is presented. A total of 59 neuropeptides were validated by liquid chromatography-tandem mass spectrometry in brain and nervous ganglia from T. infestans, revealing the existence of differential post-translational modifications, extended and truncated forms. The results suggest a high sequence conservation in some neuropeptide systems in triatomines, whereas remarkable differences occur in several others within the core domains. Comparisons of the basal expression levels for several neuropeptide precursor genes between pyrethroid sensitive and resistant population of T. infestans are also presented here, in order to introduce a proof of concept to test the involvement of neuropeptides in insecticide resistance. From the precursors tested, NVP and ITG peptides are significantly higher expressed in the resistant population. To our knowledge, this is the first report to associate differential neuropeptide expression with insecticide resistance. The information provided here contributes to creating conditions to widely extend functional and genetic studies involving neuropeptides in triatomines.
authors.affiliation: Laboratory of Insect Neurobiology, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 N(o). 1459, CP: 1900, La Plata, Argentina.
authors.forename: Lucila
authors.initials: L
authors.lastname: Traverso
authors.affiliation: Laboratory of Insect Neurobiology, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 N(o). 1459, CP: 1900, La Plata, Argentina.
authors.forename: Ivana
authors.initials: I
authors.lastname: Sierra
authors.affiliation: Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco D. Prédio do CCS, Ilha do Fundão, Rio de Janeiro 21941-902, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Sterkel
authors.affiliation: Center of Experimental and Applied Endocrinology, CONICET-CCT La Plata, National University of La Plata, 60 and 120 Street, CP: 1900, La Plata, Argentina.
authors.forename: Flavio
authors.initials: F
authors.lastname: Francini
authors.affiliation: Laboratory of Insect Neurobiology, Regional Center for Genomic Studies, Faculty of Exact Sciences, National University of La Plata, Bvd 120 N(o). 1459, CP: 1900, La Plata, Argentina. Electronic address: sheila.ons@presi.unlp.edu.ar.
authors.forename: Sheila
authors.initials: S
authors.lastname: Ons
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling; D007305:Insecticide Resistance / Q000235:genetics; D009479:Neuropeptides / Q000235:genetics* / Q000378:metabolism*; D013045:Species Specificity; D014224:Triatoma / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D009479:Neuropeptides
keywords: Chagas' disease; Insects; LC-MS/MS; Neuropeptides; Peptidomics