OBJECTIVETo assess the DNA damage in mouse sperms induced by exogenous BDE-209 and explore the possible mechanism of BDE-209 in affecting normal zygote development.

METHODSMouse sperms were harvested from the epididymal tail and suspended in HTF medium for a 90-min exposure to BDE-209 at varied concentrations of 0, 2.5, 5.0, 10, and 20 µg/ml (groups A-E, respectively). After the exposure, the sperms were subjected to single-cell gel electrophoresis (SCGE) to assess the DNA damage.

RESULTSThe tail length of the sperms averaged 1.15 ∓ 1.27 µm in group A. Exposure to 10 and 20 µg/ml BDE-209 resulted in a significant lengthening of the sperm tails (2.13 ∓ 1.29 µm and 2.83 ∓ 2.46 µm, respectively, P<0.01) as well as increased DNA content in the tail of the cells (P<0.01). The Olive tail moment in group A was 0.270 ∓ 0.322, and increased after BDE-209 exposure to 0.453 ∓ 0.375 and 808 ∓ 0.822 in groups D and E, respectively. The tail/head length ratio in groups C, D, and E (0.077 ∓ 0.093, 0.112 ∓ 0.068, and 0.191 ∓ 0.207) were significantly greater than that in group A (0.045 ∓ 0.049). The DNA damage of the mouse sperms was directly correlated to the concentrations of BDE-209, with correlation coefficients all above 0.9.

CONCLUSIONSExogenous BDE-209 can cause mouse sperm DNA damage and lead to sperm DNA chain breakage, and this effect shows an obvious dose dependence.