Effects Of Subchronic Cadmium Toxication On DNA Methylation In Chicken

DNA Methylation is an normal chemical modification in organism,which can adjust thelevel of DNA Methylation and closely relate with the vegetoanimaldevelopment,X-chromosome inactivation,genetic expression,the development of tumor andorganismic aging.Cadmium,an received environmental poison,also can influence DNAmodification and induce the occurrence of cancer.Therefore, As the experimentalmaterials,Hyline-white hens were treated with cadmium through feed which successlyreplicated subchronic cadmium toxication in order to reveal the mechanism of the effect ofcadmium on the DNA methylation in hens.Some items about the level of DNAMethylation,the status of anti-oncogene p15 CpG, the expression of DNMT1, DNMT3a andDNMT3b mRNA in Liver and Kidney were detected and pathohistology was observated. Theresults showed as follows:1. By pathohistology and detecting cadmium contents in liver and kidney, it wascertificated that cadmium could induce tissue damage and damage mitochondria andendoplasmic reticulum from ultrastructure.2. Cadmium could increase the level of genome DNA methylation in liver and kidney,butthe level of liver was higher than kidney, the results indicate that cadmium could adjustmetabolism of DNA methylation which increase genic instability and influnce the genicexpression, it may be the mechanism of cadmium genotoxicity.3. It was first certificated that cadmium could increase the status of p15 CpG in liver andkidney by MSP, which induce the gene silencing of p15,so this may be the mechanism oftumor caused by cadmium from epigenetics.4. It was demonstrated that cadmium could increase the expression of DNMT1 andDNMT3a mRNA in liver and kidney, but no changes for the expression of DNMT3b mRNA inthe two tissue,So we can supposed the expression of DNMT1 and DNMT3a mRNA was oneof the reason for the raise level of genome DNA methylation.This paper systemly studied the effect of cadmium on DNA methylation and furtherrevealed the mechanism of the effects of cadmium on DNA methylation from genome DNAmethylation,anti-oncogene p15 and DNMTs mRNA et al.It provided the scientific theoretical foundation and experimental basis for exploring the molecule mechanism of cadmium,Also,itwill be very significant to raise the consciousness for protecting environment,to promote thedevelopment of animal husbandry, to safeguard the health of human and animals.