A micronucleus assay detects genotoxic effects of herbicide exposure in a protected butterfly species

Abstract

Lycaena dispar Hawort (Lepidoptera: Lycaenidae), a protected butterfly, is declining in Europe, but it thrives in rice fields in northern Italy. Here, agrochemical usage could threaten its long-term survival. We investigated, by micronucleus (MN) assay, the genotoxic effect of glyphosate, a common herbicide, on L. dispar larvae. Micronuclei (MNi) are DNA fragments separated from the main nucleus and represent the result of genomic damage that has been transmitted to daughter cells. In a control/treatment experiment, we extracted epithelial cells from last-instar larvae fed with Rumex spp. plants sprayed with a solution containing 3.6 g/L of glyphosate, and from larvae fed with unsprayed plants. MNi and other chromosomal aberrations—nuclear buds (NBUDs) and bi-nucleated cells—were then scored in 1000 cells/subject. Significant differences were found between glyphosate-exposed and control groups in terms of MNi and total genomic damage, but not in terms of NBUDs or bi-nucleated cells. We reported a possible genomic damage induced by glyphosate on larvae of L. dispar. For the first time, a MN assay was used in order to evaluate the genomic damage on a phytophagous invertebrate at the larval stage. Increased levels of MNi reflect a condition of genomic instability that can result in reduced vitality and in an increased risk of local extinction. Therefore, farmland management compatible with wildlife conservation is needed.

Oxidative and genotoxic effect of piperazine on Galleria mellonella (Lepidoptera: Pyralidae) hemolymph

“…This correlates strongly supported our data. A similar result to our results was also shown in the study by Santovito et al 2020. An increased MNi formation was detected after the application of nonlethal doses of the glyphosate-based herbicide Roundup to Lycaena dispar larvae, and the high MNi formation was explained as an indicator of a significantly increased level of genomic damage.…”

“…Comet assay and micronucleus formation are widely used in genotoxicity testing and biomonitoring. Increased MNi levels reflect a state of genomic instability that can lead to decreased viability and increased risk of extinction (Heng 2019, Ye et al 2019, Santovito et al 2020). According to the data obtained from our study, it was determined that the micronucleus formation increased at 0.1 and 1 g piperazine concentrations, similar to the results of MDA, GST, P450, and comet assay.…”

“…Comet assay and micronucleus formation (MNi) are widely used together in genotoxicity and biomonitoring tests. The comet assay allows to directly measure the DNA-strand breaking capacity of a tested chemical agent, while the MNi test allows to estimate the amount of induced chromosome and/or genome mutations (Hovhannisyan 2010, Santovito et al 2020). In this study, the oxidative and genotoxic effects of piperazine, an anthelmintic substance, on G. mellonella , an agricultural pest and an emerging model organism in recent years, were investigated.…”

Biodiversity-Centric Habitat Networks for Green Infrastructure Planning: A Case Study in Northern Italy

“…The GREVISLIN Project placed great emphasis on the protection of endangered species linked with river habitats, and especially on the endangered Lepidoptera Lycaena dispar (Haworth) and Maculinea teleius (Bergsträsser), as well as on their preferred habitat type, the lowland wet meadows and hay meadows [30,31]. In many parts of Europe, the populations of these two butterflies are declining, and consequently, they are of great conservation interest [32][33][34].…”

Ecotoxicological and Chemical Approach to Assessing Environmental Effects from Pesticide Use in Organic and Conventional Rice Paddies

“…Plant Protection Products (PPPs), because of their persistence, toxicity, and bioaccumulative properties are of particular concern. They might have adverse ecological effects, causing both short-term (acute) and long-term (chronic), lethal or sub-lethal biological damages; in particular, changes in behavior, metabolism, development, alteration of the food chain or habitat of non-target organisms such as amphibians, and bats, reduction in the populations of natural predators of insect pests [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. In addiction pesticides are known to lower the biodiversity and function of an ecosystem by promoting the dominance of undesired and invasive species [18].…”