Accumulation, elimination, sequestration, and genetic variation of lead (Pb2+) loads within and between generations of Drosophila melanogaster

Abstract

We examined accumulation, sequestration, elimination, and genetic variation for lead (Pb) loads within and between generations of Drosophila melanogaster. Flies were reared in control or leaded medium at various doses and tested for their Pb loads at different stages of development (larvae, eclosion, newly-eclosed adults, and mature adults). Pb loads were tested using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). We found that D. melanogaster readily accumulated Pb throughout their lifespan and the levels of accumulation increased with Pb exposure in the medium. Wandering third-instar larvae accumulated more Pb than mature adults; this phenomenon may be due to elimination of Pb in the pupal cases during eclosion and/or depuration in adults post-eclosion. The accumulated Pb in mature adults was not transferred to F1 mature adult offspring. Using a set of recombinant inbred strains, we identified a quantitative trait locus for adult Pb loads and found that genetic variation accounted for 34% of the variance in Pb load. We concluded that D. melanogaster is a useful model organism for evaluating changes in Pb loads during development, as well as between generations. Furthermore, we found that genetic factors can influence Pb loads; this provides an essential foundation for evaluating phenotypic variation induced by the toxic effects of Pb.

Lead Modulates trans- and cis-Expression Quantitative Trait Loci (eQTLs) in Drosophila melanogaster Heads

“…To mimic lead poisoning, the medium was mixed to a final concentration of 250 μM PbAc [Pb(II)(C 2 H 3 O 2 ) 2 ] for lead-containing medium or 250 μM NaAc [Na(C 2 H 3 O 2 )] for control medium. This makes the Drosophila brain contain 50–100 μg/dl lead content (Peterson et al, 2017 ). Our lab has long been using NaAc as the control for PbAc for nearly a decade, and was recommended by leaders in the lead toxicology field (Ruden et al, 2009 ).…”

“…To better understand how lead plays a role as a neurotoxin, and to identify lead-responsive genes that might be involved in lead neurotoxicity, we utilized the Drosophila melanogaster model to study the genetic effects of lead exposure during development. Our lab has already shown that Drosophila fed with 250 μM lead acetate in standard fly food, which results in lead levels of 50–100 μg/dl in tissue (Peterson et al, 2017 ), results in gene expression (Ruden et al, 2009 ), synaptic (He et al, 2009 ), and behavioral (Gupta et al, 2007 ) changes. We have previously found that lower lead levels in the food, 50 μM lead acetate, altered the uniformity of the synaptic match between the size of the motor neuron terminal and muscle fibers at larval neuromuscular junctions (Morley et al, 2003 ), and resulted in behavioral changes including courtship (Hirsch et al, 1995 ) and locomotor activity (Hirsch et al, 2003 ).…”

Assessment of bioaccumulation of cu and Pb in experimentally exposed spiders, Lycosa terrestris and Pardosa birmanica, using different exposure routes

“…Also, free Cu ions bind with thiol group of membrane protein and disrupt its structure and function (Holmstrup et al 1998;Huang et al 2012). Pb represents a risk for terrestrial organisms due its high toxicity and long-term retention time in the environment (Kumar et al 1995;Peterson et al 2017). Pb is a redox inactive metal which produce oxidative stress indirectly by binding with sulfhydryl group of proteins and cause depletion of glutathione, alteration of Ca hemostasis, DNA damage and Lipid peroxidation (Stohs and Bagchi, 1993) Spiders can accumulate large amount of metals and are generally considered as macro-concentrators (Dallinger 1993) and bioindicator of environmental pollution (Wilczek et al 2004;Jung et al 2007).…”