New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues

Comment on “New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues”

“…HgSe nanoparticles (NPs) were imaged in liver, kidneys and muscle of giant petrels [3], and their formation involves the replacement of selenocysteine ligands with selenide ligands, likely through the nucleation of multinuclear Hgx(Se,Sec)y clusters (y < 4x). The production of biominerals mediated by metalloproteins is common in nature [10], and we show below that the results of Queipo-Abad et al [1] support the composite nature of the HgSe NPs, as observed for other biominerals [11][12][13].…”

“…Through a mathematical inversion analysis of the petrel and whale isotopic data, Manceau et al [4,15] showed that the 22 δ 202 Hgt petrel values and the 89 δ 202 Hgt whale values, could be calculated with just three δ 202 Spi values, each associated with the MeHgCys, Hg(Sec)4, and HgSe species. Therefore, Equation 1 was reduced to We show below that the Queipo-Abad et al [1] data can be reinterpreted in light of the findings of the recent petrel and whale studies [4,15], which concluded that the three Hg species have a specific isotopic composition which is homogenized throughout the body. The demonstration is performed in two steps.…”

“…Queipo-Abad et al [1] isolated 37 HgSe NPs from the biological tissues of 11 giant petrels and measured the mass-dependent fractionation (MDF) of the 202 Hg isotope, expressed as δ 202 Hg [14],…”

“…Three (PGA01, PGA02, PGA03) of the six brain tissues studied by Queipo-Abad et al [1] had been analyzed previously for Hg speciation using X-ray absorption spectroscopy [3]. PGA01 contains 40 ± 6% MeHgCys + 24 ± 15% Hg(Sec)4 + 36 ± 13% HgSe, PGA02 contains 83 ± 5%…”

Dynamics of Dietary Mercury Determined by Mercury Speciation and Isotopic Composition in Dicentrarchus labrax

“…At this stage, our results do not allow us to confirm if the observed negative MDF is more related to the co-precipitation of dietary iHg directly stored in muscle, demethylation and coprecipitation of MeHg coming from liver or the diet, leaving this as an open question for future studies. This underlines the potential great scientific advance that compound-specific Hg stable isotope could bring in the future (Perrot et al, 2015;Queipo-Abad et al, 2022).…”