Use of transgenic GFP reporter strains of the nematode Caenorhabditis elegans to investigate the patterns of stress responses induced by pesticides and by organic extracts from agricultural soils

Abstract

A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk reporters to investigate the toxicity of soil pore water from two agricultural sites in south-east Spain, designated P74 (used for cauliflower production, but significantly metal contaminated) and P73(used for growing lettuce, but with only background levels of metals). Both soil pore water samples induced all five test genes to varying extents, yet artificial mixtures containing all major metals present had essentially no effect on these same transgenes. Soluble organic contaminants present in the pore water were extracted with acetone and dichloromethane, then after evaporation of the solvents, the organic residues were redissolved in ultrapure water to reconstitute the soluble organic components of the original soil pore water. These organic extracts induced transgene expression at similar or higher levels than the original pore water. Addition of the corresponding metal mixtures had either no effect, or reduced transgene expression towards the levels seen with soil pore water only. We conclude that the main toxicants present in these soil pore water samples are organic rather than metallic in nature. Organic extracts from a control standard soil (Lufa 2.2) had negligible effects on expression of these genes, and similarly several pesticides had little effect on the expression of a constitutive myo-3::GFP transgene. Both the P73 and P74 sites have been treated regularly with (undisclosed) pesticides, as permitted under EU regulations, though other (e.g. industrial) organic residues may also be present.Introduction.

Pollution by metals and toxicity assessment using Caenorhabditis elegans in sediments from the Magdalena River, Colombia

“…Approximately 30 g of dried sediment were mixed with 30 mL of ultrapure water (UW) and left overnight at 4 C (Anbalagan et al, 2012(Anbalagan et al, , 2013Power and De Pomerai, 1999). The wet sediment was then divided among four 20 mL syringe cylinders plugged with a stainless steel mesh disc and glass wool (Hasegawa et al, 2008).…”

“…Equal aliquots of worms on all stages were placed into black non-fluorescent U-bottomed 96-well microplates with the samples and UW as control. Plates were incubated at 20 C, and readings were done after 4 and 24 h. Fluorescence was quantified by using a PerkineElmer Victor 1420 multilevel plate reader using 485/525 nm as excitation/emission wavelengths, respectively (Anbalagan et al, 2012(Anbalagan et al, , 2013Power and De Pomerai, 1999).…”

“…Its use as a biological model in environmental assessments toxic allows the determination of several endpoints including survival, growth, reproduction, fertility, locomotion, survival, protein expression, gene expression and DNA damage, among other (Anbalagan et al, 2012;Megalou and Tavernarakis, 2009;TejedaBenitez and Olivero-Verbel, 2016). Transgenic nematodes carrying the GFP gene are also used in studies of biochemical pathways, including response to heavy metals (Du and Wang, 2009;Helmcke et al, 2009), cellular and oxidative stress (Bianchi et al, 2015;Salgueiro et al, 2014;Wang et al, 2014a), and xenobiotic detoxification (Anbalagan et al, 2012(Anbalagan et al, , 2013.…”

“…elegans is highly responsive to metals by expressing metallothioneins (MTs) mtl-1 and mtl-2, small cysteine-rich proteins with strong affinity to metals, involved in metal sequestration, transportation, detoxification, and protection against oxidant agents (H€ ockner et al, 2011;Monteiro and Brinke, 2014;Wang et al, 2010). Another group is heat shock proteins (HSP) that work as molecular chaperones, supporting refolding and restoring of denatured proteins and aiding protein synthesis (Anbalagan et al, 2013;Helmcke and Aschner, 2010).…”

“…C. elegans has five genes that code for SODs: sod-1 to sod-5, being Cu/Zn SODs sod-1 and sod-4 used in assays with C. elegans (Back et al, 2010). CYPs are proteins involved in xenobiotic stress response, being cyp-29A2, cyp-34A9, and cyp-35A2, representative members of this family (Anbalagan et al, 2013). GSTs consists of ubiquitous, dimeric proteins involved in the detoxification of endogenous and xenobiotic compounds by glutathione conjugation, peroxidase activity or passive binding, supporting the conversion of GSH to electrophilic GS À , which binds to toxic compounds and leads their excretion (Campbell et al, 2001).…”