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Abstract :
[en] In this study, e ects of two androgens (tributyltin and testosterone),
one antiandrogen (cyproterone acetate) and one estrogen (chlordecone) on
growth and reproduction were investigated in the hermaphrodite gastropod
Lymnaea stagnalis. In this study, exposure to a range of concentrations (ng/l
to μg/l) of each chemical was performed during 21 days. e number of
clutches and the number of eggs per clutch were monitored. A decrease in
clutches laid per snail was observed after exposure to tributyltin (540, 1180
and 2600 ng/l) and chlordecone (10, 22, 50 and 110 μg/l). A signi cant
decrease in egg laid per snail was observed after exposure to tributyltin (540,
1180 and 2600 ng/l) and chlordecone (50 and 110 μg/l). An increase of egg
abnormalities ratio in exposed snails (atrophied albumen, polyembryonicity,...)
was observed in L. stagnalis following exposure to testosterone (2, 22,
50 and 110 ng/l), cyproterone acetate (4,5 and 50 μg/l), tributyltin (110
and 244 ng/l) and chlordecone (4,5 and 10 μg/l). Investigation of alteration
in protein expression in exposed snails was performed using proteomic
analysis such as 2D-DIGE. Mass spectrometry identi cation was performed
on proteins with altered expression. We could establish correlation between
reproductive endpoints and changes in proteins involved in egg formation
and in egg laying were underlined. Egg yolk ferritin, the main protein of egg
yolk, was shown to be reduced signi cantly in relationship with a decrease
of egg yolk quality after exposure to tributyltin 540 ng/l and cyproterone
acetate 4,5 μg/l. Ovipostatin, a protein proved to reduce egg masses, was
signi cantly over expressed in snails exposed to 50 μg/l of chlordecone and
were in relationship with a reduction of clutches laid by individuals. Further
western blot analysis on those proteins involved in the reproduction are
underway. ese analysis will enable us to con rm and re ne with more
speci city the 2D-DIGE results for the selected proteins. e results of this
study can help to establish new biomarkers of exposure of endocrine disruptors
in freshwater environment and can provide new insight on mode of
action of endocrine disruptors in L. stagnalis.
