Micronucleus Test Reveals Genotoxic Effects in Bats Associated with Agricultural Activity

Abstract

Bats play a vital role in our ecosystems and economies as natural pest‐control agents, seed dispersers, and pollinators. Agricultural intensification, however, can impact bats foraging near crops, affecting the ecosystem services they provide. Exposure to pesticides, for example, may induce chromosome breakage or missegregation that can result in micronucleus formation. Detection of micronuclei is a simple, inexpensive, and relatively minimally invasive technique commonly used to evaluate chemical genotoxicity but rarely applied to assess wildlife genotoxic effects. We evaluated the suitability of the micronucleus test as a biomarker of genotoxicity for biomonitoring field studies in bats. We collected blood samples from insectivorous bats roosting in caves surrounded by different levels of disturbance (agriculture, human settlements) in Colima and Jalisco, west central Mexico. Then, we examined the frequency of micronucleus inclusions in erythrocytes using differentially stained blood smears. Bats from caves surrounded by proportionately more (53%) land used for agriculture and irrigated year‐round had higher micronucleus frequency than bats from a less disturbed site (15% agriculture). We conclude that the micronucleus test is a sensitive method to evaluate genotoxic effects in free‐ranging bats and could provide a useful biomarker for evaluating risk of exposure in wild populations. Environ Toxicol Chem 2021;40:202–207. © 2020 SETAC

Pesticide Exposure Risks to Chiropteran Species and the Impacts on Emerging Zoonotic Diseases

“…Micronucleus tests conducted in the insectivorous bat species, Parnell's mustached bat (Pteronotus mexicanus), documented that P. mexicanus roosting in caves surrounded by agriculture and foraging over pesticide treated fields, had a higher number of micronuclei than bats roosting and foraging in areas where no more than 15% of the surrounding land-use was agriculture [111]. Another study assessing micronuclei and other nuclear abnormalities in insectivorous, frugivorous, and nectivorous bats discovered that nectivorous bats did not have any significant nuclear changes in agricultural or urban areas [112].…”

Sampling methodology influences habitat suitability modeling for chiropteran species

“…Landscape‐level research for Chiropteran species is necessary to identify critical habitats, patches, and corridors to target management interventions in the face of multiple compounding factors threatening North American bat populations (Bellamy et al, 2013; Rodhouse et al, 2019; Sandoval‐Herrera et al, 2020). While the impact of multiple detection types has been studied for occupancy modeling, there has been little research on landscape‐level effects of multiple data types on habitat modeling, particularly for chiropteran species (Banner et al, 2018; Clement et al, 2014; Rojas et al, 2019).…”

Vicia–Micronucleus Test Application for Saline Irrigation Water Risk Assessment

“…Salinity has been found to decrease cell division rate and, consequently, cell number and to induce micronuclei and chromosome/nucleus abnormalities responsible for plant size reduction [ 11 ]. The Micronucleus Test (MCN Test) is used to assess the toxic potential of geno-toxic agents and it allows for control of mitosis [ 12 , 13 , 14 , 15 ]. From a practical point of view, the MCN Test is fast since an exposure of only 48 h is required, not expensive compared to more advanced laboratory tests, requires only a microscope (and camera), and allows for assessment of genotoxic parameters (cells in division, MCN, and chromosome/nucleus aberrations) in the same slide [ 15 ].…”