Title: | Infochemicals released by Daphnia magna fed on Microcystis aeruginosa affect mcyA gene expression |
Author(s): | Pineda-Mendoza RM; Zuniga G; Martinez-Jeronimo F; |
Address: | "Laboratorio de Hidrobiologia Experimental, Departamento de Zoologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prol. Carpio esq. Plan de Ayala s/n, Col. Sto. Tomas, Mexico, D.F. 11340, Mexico; Laboratorio de Variacion Biologica y Evolucion, Departamento de Zoologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prol. Carpio esq. Plan de Ayala s/n, Col. Sto. Tomas, Mexico, D.F. 11340, Mexico. Laboratorio de Variacion Biologica y Evolucion, Departamento de Zoologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prol. Carpio esq. Plan de Ayala s/n, Col. Sto. Tomas, Mexico, D.F. 11340, Mexico. Laboratorio de Hidrobiologia Experimental, Departamento de Zoologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prol. Carpio esq. Plan de Ayala s/n, Col. Sto. Tomas, Mexico, D.F. 11340, Mexico. Electronic address: ferjeronimo@hotmail.com" |
DOI: | 10.1016/j.toxicon.2014.01.008 |
ISSN/ISBN: | 1879-3150 (Electronic) 0041-0101 (Linking) |
Abstract: | "Microcystins (MCs) are toxic heptapeptides produced by cyanobacteria during blooms that are noxious to diverse organisms, from bacteria to vertebrates. Specifically in daphnids, they cause reduced growth, a low reproductive rate, and, in extreme cases, death; however, different infochemicals released by cladocerans stimulate MCs synthesis. Ecological cyanobacteria-daphnids interactions are complex and not clear yet. In this study, we evaluated the effects of infochemicals released by Daphnia magna neonates and adults fed with different concentrations of Microcystis aeruginosa on population growth of strains Ch10 and UTEX LB2385 of M. aeruginosa, mcyA gene expression in real time qPCR, and the intracellular concentration of MCs. In addition, we assessed the relation between the cellular diameter and the intracellular concentration of MCs in both strains. Chlorophyll content per cell was affected by the presence of infochemicals from D. magna neonates and adults. mcyA gene was significantly overexpressed in the early stages of population growth (5 days) in all treatments with strain UTEX LB2385, whereas overexpression was observed in strain Ch10 at the end stage of the exponential and stationary phases (10 and 15 days). Intracellular concentration of MCs varied with the tested factor. Results suggest that the increase in mcyA gene expression and in MCs production could be defense mechanisms against the consumption by D. magna. Results also demonstrate the physiological plasticity among Microcystis strains, which could explain the permanence and dominance of this genus in toxic blooms" |
Keywords: | "Animals Bacterial Proteins/*genetics/metabolism Chlorophyll/metabolism Chlorophyll A Computational Biology DNA, Bacterial/genetics Daphnia/*chemistry *Gene Expression Microcystins/toxicity Microcystis/*genetics/metabolism Bloom Cladocera Cyanobacteria Gen;" |
Notes: | "MedlinePineda-Mendoza, Rosa Maria Zuniga, Gerardo Martinez-Jeronimo, Fernando eng Research Support, Non-U.S. Gov't England 2014/01/29 Toxicon. 2014 Mar; 80:78-86. doi: 10.1016/j.toxicon.2014.01.008. Epub 2014 Jan 24" |