Functional significance of genotoxicity in fish germ cells

• Main Authors: Devaux, Alain, Gillet, Christian, Fiat, Luc, Santos, Raphaël, Sanchez, Wilfried, Bony, Sylvie
• Other Authors: Laboratoire des Sciences de l'Environnement, École Nationale des Travaux Publics de l'État (ENTPE), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry ), Institut National de l'Environnement Industriel et des Risques (INERIS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2010
• Subjects: FISH; GENOTOXICITY; REPRODUCTION; SPERM; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDE]Environmental Sciences; Arctic; Arctic charr; Salvelinus alpinus
• Online Access: https://ineris.hal.science/ineris-00973575; https://ineris.hal.science/ineris-00973575/document; https://ineris.hal.science/ineris-00973575/file/2010-136_hal.pdf

The aquatic environment is becoming increasingly contaminated by pollutants having a genotoxic potential towards organisms and in particular in fish. Such genotoxins are prone to affect directly offspring or indirectly through the reproductive process. All this could influence recruitment rate and hence the population dynamics. However, assessment of the ecological risks associated with environmental genotoxic exposure is usually based on individual responses. Thus, there is a need for a better understanding of the long term and population level implications of genotoxic insults in fish. While low levels of DNA damage in somatic cells and oocytes can be efficiently repaired, mature sperm cells, i.e. spermatozoa, are susceptible to accumulate damage due to their lack of repair capacity. The present work aims to track the transfer of toxic effects across generations by studying the link between the level of DNA damage in fish sperm, and the rate of development abnormalities measured in the offspring after parental exposure to the model genotoxicant MMS. Three different fish species were chosen based either on their ecological importance or on their reproduction behavior, respectively brown trout (Salmo trutta), Arctic charr (Salvelinus alpinus) and threespine stickleback (Gasterosteus aculeatus). Results show a significant increase in sperm DNA damage measured with the comet assay in exposed organisms. This damage did not impact on fertilization success but led further to a significant increase in embryo abnormality rate at early embryonic and late larval stages, and further delayed growth in exposed group compared to the control.