Evolution of the venomous caterpillars of the genus Lonomia and analysis of their toxicity using last generation molecular techniques

Caterpillars of the genus Lonomia (family Saturniidae) are covered in scoli filled with venom. The venom is capable of producing hemorrhagic syndrome in humans that can lead patients to develop kidney failure, brain damage and, in severe cases, death. Accidents have been attributed to two species, however, genetic identification of caterpillars associated to accidents in Colombia have led to the discovery of at least three different species capable of produce hemorrhagic syndromes. Phylogenetic relationships among these species and their venom¿s action mechanism are still unknown. Under this context, the objectives of this thesis were to: (1) propose a time-calibrated phylogeny for the genus Lonomia (2) evaluate altered metabolites of cells exposed to venom from different species of Lonomia. To achieve the first objective, we sequenced ultraconserved elements (UCEs) from Lonomia samples representing 48 different species and reconstruct the phylogeny. The phylogeny obtained is nearly comprehensive and supports the division of the genus into three species-groups and an additional lineage represented by Lonomia beneluzi. Our phylogenetic hypothesis reveals that the species involved in human envenomation are not monophyletic and belong to both the achelous- and obliqua-group suggesting that more species of Lonomia may be involved in human accidents. To achieve the second objective, VERO cells were exposed to venom of 3 Lonomia species: L. casanarensis, L. orientoandensis and L. orientocordillera. We used a concentration of 30 ?g/ml and two exposure times (2h and 24h). Metabolites of VERO cells were extracted and measured using liquid chromatography coupled to high resolution-mass spectrometry. We were able to identify 96 altered metabolites. We found a downregulation of glutathione and upregulation of prostaglandins in cells exposed to the venoms of L. orientocordillera and L. casanarensis suggesting their capability to cause oxidative stress and inflammation.

• Autores: Díaz Díaz, Juana Maria
• Fecha de publicación: 2021
• Institución: Universidad de los Andes
• Repositorio: Séneca: repositorio Uniandes
• Idioma: spa
• OAI Identifier: oai:repositorio.uniandes.edu.co:1992/54994
• Acceso en línea: http://hdl.handle.net/1992/54994
• Palabra clave: Filogenia; Lonomia; Envenenamiento humano; Estrés oxidativo; Biología
• Rights: openAccess
• License: http://creativecommons.org/licenses/by-nc-sa/4.0/