Effects On The Sperm Enzyme Activity, DNA Integrity And Histone Expression Of Eriocheir Sinensis By Atrazine Exposure

Eriocheir sinensis known as crab is an important economic aquaculture animals in China. But in recent years, with the development of aquaculture of E. sinensis, precocity and germplasm degradation had cropped up. Atrazine is a kind of herbicide which is used widely. At present, it has confirmed that atrazine is an endocrine disruptor, and it can damage the reproductive and immune systems. Therefore, mature male E.sinensis which was dealt with atrazine at different concentration(0.001, 0.01, 0.1 and 1 mg/L) in vivo and vitro was used as experimental materials to detect the effect of atrazine on the sperm quality from the aspects of enzyme activity, DNA integrity, the expression of histone and H3K79 methyltransferase.After two weeks atrazine expose, spectrophotometry and zymography were used to detected spermatophores lactate dehydrogenase and acid phosphatase activity. The results showed that whether detected with spectrophotometry or zymography, the maximum of acid phosphatase activity was emerged in 0.1mg/L atrazine-treated group. Sperm chromatin dispersion(SCD) results showed that sperm DNA damage can be caused by atrazine exposure in vitro, and the proportion of DNA damage sperm increased with the increasing of atrazine concentration. RT-q PCR results showed that histone H3 and H4 gene expression levels in different atrazine-treated groups were different. Histone H3 and H4 gene expression levels in 0.1 mg/L atrazine-treated group was significantly higher than the control groups. The expression of H3K79 methytransferase was decreased significantly in 0.1 mg/L atrazine-treated group.Sperm lactate dehydrogenase and acid phosphatase activity is an important indicator of sperm quality evaluation. Histone and methylation modification play an important role on the process of spermatogenesis, and the abnormal changes of them can cause male sterility. Sperm DNA integrity is basic condition to confirm the effective heredity of the male parental genetic traits. These results showed that atrazine(0.1 mg/L) may affect E. sinensis sperm lactate dehydrogenase and acid phosphatase activity, while it can affect the sperm histone H3, H4 and H3K79 methyltransferase gene expression levels significantly. Meanwhile, it can cause sperm DNA damage. And these effects will lead to the decreasing of sperm quality and germplasm degradation of E. sinensis.