Toxic effects of microcystin-LR on the reproductive system of male Rana nigromaculata in vitro

► Microcystin-LR (MCLR) can induce reproductive toxic effects on male Rana nigromaculata in vitro. ► MCLR can induce distention of mitochondria, endoplasmic reticulum, and Golgi apparatus in the testis of R. nigromaculata. ► The antioxidant defense system of the testis in R. nigromaculata can quickly respond to oxidative stress induced by MCLR. ► Expressions of P450 aromatase and SF-1 genes are important toxic mechanisms of male R. nigromaculata exposed to MCLR. This study aims to demonstrate that microcystin-LR (MC-LR) has toxic effects on the reproductive system of male Rana nigromaculata in vitro. R. nigromaculata were treated with 0, 0.1, 1, 10, and 100nmol/L of MC-LR for 6h. Results show that exposure to 1nmol/L to 100nmol/L of MC-LR decreased sperm motility and number of sperm cells and increased the sperm abnormality rate, whose values were significantly different from those of the control (P