Responses of lipid metabolism in Rana chensinensis tadpoles under lead (Pb) stress

Lead (Pb) is a toxic contaminant ubiquitously present in aquatic ecosystems. Unfortunately, studies on the effects of Pb on lipid metabolism and gene expression in amphibians are limited. Here, lipidomic and hepatic transcriptomic analyses were performed on Rana chensinensis tadpoles exposed to 20 and 200 μg/L Pb. Our data demonstrated that phosphatidylcholine (PC) species were significantly reduced in the Pb20 group and significantly increased in the Pb200 group. The decrease in PC content may be related to membrane damage in tadpoles. Meanwhile, liver transcriptome profiling revealed that differentially expressed genes induced by different concentrations of Pb treatment were simultaneously enriched in Staphylococcus aureus infection pathway, with significantly increased expression of FB, C3, and MHC-II in the Pb20 group and C3AR1 in the Pb200 group. Moreover, Pb exposure resulted in liver damage (e.g., lipid droplet accumulation) and significantly reduced body size in tadpoles at metamorphosis, which may have increased their susceptibility to mortality. This study is the first to investigate the deleterious effects of Pb on lipid metabolism and hepatic gene expression in tadpoles, shedding light on the potential molecular mechanisms of Pb toxicity in amphibians.