Screening of potential uranium protein targets in fish ovaries after chronic waterborne exposure: Differences and similarities between roach and zebrafish

• Published in: Journal of environmental radioactivity Vol. 222; p. 106365
• Main Authors: Frelon, Sandrine, Simon, Olivier, Eb-Levadoux, Yvan, Mounicou, Sandra
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020; Elsevier
• Subjects: Biodiversity and Ecology; Biomolecules; Ecotoxicology; Environmental Sciences; Life Sciences; Ovary; Roach; Speciation; Toxicology; Uranium; Vitellogenin; Zebrafish; Ovary; Uranium; Biomolecules; Zebrafish; Vitellogenin; Speciation; Roach
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2020.106365

Concentration of uranium (U), a naturally encountered radioactive element in earth's crust, can be enhanced in freshwater ecosystems (μg.L−1 – mg.L−1) due to various anthropogenic activities. The consequent aquatic organism exposure to U leads to its accumulation in all organs, particularly in the gonad, and in subcellular fractions (mainly the cytosol); then it is known to affect fish at several biological levels, and more particularly, at a reproduction endpoint, with a decrease in the total number of eggs, spawn events and larvae survival. The understanding of U reprotoxicity requires the fine knowledge of its speciation at molecular level, i.e., its interaction with cytosolic biomolecules. In this study, we focus on the U-protein interactions in gonads. A non-denaturating extraction protocol combined with size exclusion chromatography (SEC) allowed the separation of metal-protein complexes in ovaries of U-contaminated wild roaches before their elemental detection (ICP MS). This enables unprecedented information to be obtained about U distribution in ovaries of autochthonous fish, Rutilus rutilus, which is different in some points from that obtained in the model species, Danio rerio under controlled laboratory conditions at a similar concentration level. Finally, the ability to transpose results from model to autochthonous fish was briefly discussed. •Comparison of U-protein distribution and U–P coelutions between wild roach and zebrafish model.•The distribution of uranium between all identified U fractions in roach is more homogeneous.•Linear relationship between phosphorus and uranium percentages in the main U fraction.•Vitellogenin and its fragments, including maturation products, are expected to bind U.•Reproduction cycle and protein content in ovaries may play a key role in the uranium distribution.