Arsenic-related oxidative stress in experimentally-dosed wild great tit nestlings

Does arsenic contamination affect DNA methylation patterns in a wild bird population? An experimental approach

“…As reported in Sánchez-Virosta et al (2020; 2018), dietary arsenic treatment successfully increased arsenic load as fecal arsenic levels were on average 10 times higher in arsenic exposure compared to control group (average±SD ppm: control 0.51±0.50, As exposure 4.92±4.57, t 15.4 = −3.83, p = 0.0015), and increased levels were also found in internal tissues.…”

“…The arsenic exposure, dosages and sampling are described in detail in Sánchez-Virosta et al (2020; 2018). In short, the experiment was conducted in a nest-box population in western Finland, with known history of very low pollution levels (Eeva, Ryömä, & Riihimaki, 2005).…”

“…Breeding was monitored, and from day 3 after hatching until day 14 whole broods were subjected to daily oral dosing with the following treatments: arsenic treatment (1 μg As/g bodymass, N = 16 broods) or control treatment (distilled water, N = 16 broods). The dose aimed to represent environmentally relevant exposure levels occurring in polluted areas in Europe: It was estimated combining data from several sources, such as (i) the lowest-observed-adverse-effect level for different effects on mammals, (ii) fecal arsenic levels reported for great tits at some metal polluted sites (reviewed in Sánchez-Virosta et al, 2015), (iii) arsenic concentrations of food items (moth larvae, spiders and beetles) collected directly from parent great tits feeding their nestlings in the polluted area (Sánchez-Virosta et al, 2018, 2020), and (iv) a pilot experiment Sánchez-Virosta et al, 2018). Fecal matter was sampled 8 days after hatching for metal analyses (see below).…”

“…Arsenic exposure has been reported to negatively affect multiple fitness-related traits (growth, physiology, behavior and even egg-laying) in several birds species (reviewed in Sánchez-Virosta et al, 2015). For great tits specifically, we have previously reported (using the same experimental protocol) that arsenic exposure increased nestling mortality, reduced wing growth (Sánchez-Virosta et al, 2018) and decreased an intracellular antioxidant, catalase, in nestlings (Sánchez-Virosta et al, 2020). More specifically, we here experimentally exposed nestlings in non-polluted sites to environmentally relevant levels (1μg/g body mass) of dietary arsenic during the entire post-hatching growth period, and compared their DNA methylation levels to respective controls.…”

Antioxidant defence barrier of great tit Parus major nestlings in response to trace elements

“…Many works have investigated P. major as a bioindicator of environmental pollution or measured the impact of heavy metals on different parameters determining the condition and reproductive success of birds (Dauwe et al 2004;Dauwe et al 2006). In recent years, a few papers have focused on oxidative stress as a secondary consequence of environmental pollution, including the effect of heavy metals (Koivula et al 2011;Espín et al 2014;Herrera-Dueñas et al 2017;Stauffer et al 2017;Sanches-Virosta et al 2019, 2020. It is confirmed that chemical elements are involved in generating reactive oxygen species (ROS) such as hydroxyl radical (OH -• ), superoxide radical (O 2 -• ), or hydrogen peroxide (H 2 O 2 ) (Koivula and Eeva 2010;Espín et al 2014;de la Casa-Resino et al 2015).…”