| Title: | The Differential Expression of Mevalonate Pathway Genes in the Gut of the Bark Beetle Dendroctonus rhizophagus (Curculionidae: Scolytinae) Is Unrelated to the de Novo Synthesis of Terpenoid Pheromones |
| Author(s): | Sarabia LE; Lopez MF; Obregon-Molina G; Cano-Ramirez C; Sanchez-Martinez G; Zuniga G; |
| Address: | "Laboratorio de Variacion Biologica y Evolucion, Departamento de Zoologia, Escuela, Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prolongacion de Carpio y Plan de Ayala s/n, Miguel Hidalgo, Mexico City CP 11340, Mexico. Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Campo Experimental Pabellon, Km. 32.5 Carr. Ags.-Zac., Pabellon de Arteaga, Ags. CP 20660, Mexico. Laboratorio de Variacion Biologica y Evolucion, Departamento de Zoologia, Escuela, Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prolongacion de Carpio y Plan de Ayala s/n, Miguel Hidalgo, Mexico City CP 11340, Mexico. capotezu@hotmail.com" |
| ISSN/ISBN: | 1422-0067 (Electronic) 1422-0067 (Linking) |
| Abstract: | "Bark beetles commonly produce de novo terpenoid pheromones using precursors synthesized through the mevalonate pathway. This process is regulated by Juvenile Hormone III (JH III). In this work, the expression levels of mevalonate pathway genes were quantified after phloem feeding-to induce the endogenous synthesis of JH III-and after the topical application of a JH III solution. The mevalonate pathway genes from D. rhizophagus were cloned, molecularly characterized, and their expression levels were quantified. Also, the terpenoid compounds produced in the gut were identified and quantified by Gas Chromatography Mass Spectrometry (GC-MS). The feeding treatment produced an evident upregulation, mainly in acetoacetyl-CoA thiolase (AACT), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), phosphomevalonate kinase (PMK), and isopentenyl diphosphate isomerase (IPPI) genes, and males reached higher expression levels compared to females. In contrast, the JH III treatment did not present a clear pattern of upregulation in any sex or time. Notably, the genes responsible for the synthesis of frontalin and ipsdienol precursors (geranyl diphosphate synthase/farnesyl diphosphate synthase (GPPS/FPPS) and geranylgeranyl diphosphate synthase (GGPPS)) were not clearly upregulated, nor were these compounds further identified. Furthermore, trans-verbenol and myrtenol were the most abundant compounds in the gut, which are derived from an alpha-pinene transformation rather than de novo synthesis. Hence, the expression of mevalonate pathway genes in D. rhizophagus gut is not directed to the production of terpenoid pheromones, regardless of their frequent occurrence in the genus Dendroctonus" |
| Keywords: | Animals *Eating Female Gastrointestinal Tract/metabolism/physiology *Gene Expression Regulation Hydroxymethylglutaryl CoA Reductases/genetics/metabolism Male Metabolic Networks and Pathways/*genetics Mevalonic Acid/metabolism Pheromones/*biosynthesis Terp; |
| Notes: | "MedlineSarabia, Laura Elisa Lopez, Maria Fernanda Obregon-Molina, Gabriel Cano-Ramirez, Claudia Sanchez-Martinez, Guillermo Zuniga, Gerardo eng CONACyT-CB 2012/181337/Consejo Nacional de Ciencia y Tecnologia/ Switzerland 2019/08/21 Int J Mol Sci. 2019 Aug 17; 20(16):4011. doi: 10.3390/ijms20164011" |
