Copper influence on bank vole's (Myodes glareolus) sexual behavior

Cadmium induces testosterone synthesis disorder by testicular cell damage via TLR4/MAPK/NF-κB signaling pathway leading to reduced sexual behavior in piglets

Cadmium (Cd) is a highly toxic metal pollutant that can endanger the life and health of animals. Toll-like receptor 4 (TLR4) can result in testicular cell damage by positively regulating mitogen-activated protein kinase (MAPK)/nuclear factor-kappaB (NF-κB) signaling pathway. Meanwhile, Testosterone (T) synthesis disorder can affect sexual behavior. However, the harmful influence of Cd on animal sexual behavior during its growth and development and the role of TLR4/MAPK/NF-κB signaling pathway in testicular cell damage and testosterone production remained poorly understood. Forty-two-day-old male piglets were fed with diets that contained CdCl₂ (20 mg Cd/kg) for 40 days to explore the toxic effects of Cd on sexual behavior. The results showed that Cd activated TLR4, promoted MAPK (p-ERK, p-JNK, and p-p38)/NF-κB expression, induced apoptosis (Caspase-3, Cleaved Caspase3, Bax, Cyt-c, and Caspase-9 expression increased, but Bcl-2 expression decreased) and necroptosis (MLKL, RIPK1, and RIPK3 expression increased) in piglet testis. In addition, Cd exposure decreased mRNA expression of STAR, CYP11A1, 3β-HSD, CYP17A1, and 17β-HSD of testis and the concentrations of T and thyroid-stimulating hormone (TSH). Both the mRNA and protein expression levels of the major genes in TLR4/MAPK/NF-κB signaling pathway, apoptosis signaling pathway, and necroptosis signaling pathway increased significantly and the expression levels of testosterone decreased gradually in pig Leydig cells cultured in vitro after being treated with different concentrations of Cd. Moreover, Cd reduced sexual behavior (the parameters of sniffing, chin resting, and mounting decreased) in piglets. In conclusion, Cd induced testicular cell damage via TLR4/MAPK/NF-κB signaling pathway leading to testosterone synthesis disorder and sexual behavior reduction in piglets.

The capability of Bacillus pseudomycoides from soil to remove Cu(II) in water and prevent it from entering plants

AIMS

Copper ion is widespread in wastewater and threatens the condition and human health. Micro-organisms have unique advantages to remove heavy-metal ions from water, but are rarely reported in the removal of copper ion. This aims to develop micro-organisms that can remove copper ion in water, characterize their properties and analyse their potential application in practice.

METHODS AND RESULTS

Sewage sludge was used as the source to isolate wild bacteria that can remove copper ion in water. The most efficient strain was screened out from 23 obtained isolates, identified as Bacillus pseudomycoides and coded as C6. The properties of C6 in the removal of copper ion in water were investigated in the aspects of reaction conditions, reaction groups, reaction dynamic and the application in oat planting. The reaction at pH 7 within 10 min yielded the highest removal rate of copper ion, 83%. The presence of lead ion in the reaction system could promote the removal rate of copper ion. Carboxyl groups and amidogen of C6 biomass were mainly involved in the removal of copper ion. The removal of copper ion was in accord with single-layer adsorption and Langmuir adsorption isotherm model. In application, C6 biomass reduced the copper content in the oat seedlings grown in copper ion containing water by more than seven times.

CONCLUSIONS

B. pseudomycoides C6 can efficiently remove copper ion in water and inhibit it from entering plants.

SIGNIFICANCE AND IMPACT OF STUDY

This is the first time to report the capability of B. pseudomycoides to remove copper ion in water, which is also more efficient than the currently reported chemical and biological methods.