Project description:Trophoblast stem cells (TSCs) are derived from the trophoectoderm of blastocysts and maintain ability to self-renewal and differentiation. TSC is a good model to research placenta development in vitro. It will contribute to understanding and improving cloned placentomegaly to compare the transcription and methylation between cloned and natural fertilized embryos throughout TSC derivation process. In the present study, we used SCNT (NT) and SCNT with HDACi treatment (SNT) as cloned groups and natural fertilized (NF) embryos to derive TSCs and chosed 5-time points to peform RNA-seq and RRBS. We found only NT got a barriar in TSC maintenace and both cloned groups exhited abnormal accumulating DNA methylation and it might be resiponsible for some malformations of cloned placentas.
Project description:Trophoblast stem cells (TSCs) are derived from the trophoectoderm of blastocysts and maintain ability to self-renewal and differentiation. TSC is a good model to research placenta development in vitro. It will contribute to understanding and improving cloned placentomegaly to compare the transcription and methylation between cloned and natural fertilized embryos throughout TSC derivation process. In the present study, we used SCNT (NT) and SCNT with HDACi treatment (SNT) as cloned groups and natural fertilized (NF) embryos to derive TSCs and chosed 5-time points to peform RNA-seq and RRBS. We found only NT got a barriar in TSC maintenace and both cloned groups exhited abnormal accumulating DNA methylation and it might be resiponsible for some malformations of cloned placentas.
Project description:BACKGROUND: Epigenetic modifications (especially altered DNA methylation) resulting in altered gene expression may be one reason for development failure or abnormalities in cloned animals, but the underlying mechanism of the abnormal phenotype in cloned piglets remains unknown. Some cloned piglets in our study showed abnormal phenotypes such as large tongue (longer and thicker), weak muscles, and exomphalos. Here we conducted DNA methylation (DNAm) immunoprecipitation and high throughput sequencing (MeDIP-seq) and RNA sequencing (RNA-seq) of muscle tissues of cloned piglets to investigate the relationship of abnormal DNAm with gene dysregulation and the unusual phenotypes in cloned piglets. RESULTS: Analysis of the methylomes revealed that abnormal cloned piglets suffered more hypomethylation than hypermethylation compared to the normal cloned piglets, although the DNAm level in the CpG Island was higher in the abnormal cloned piglets. Some repetitive elements, such as SINE/tRNA-Glu Satellite/centr also showed differences. We detected 1,711 differentially expressed genes (DEGs) between the two groups, of which 243 genes also changed methylation level in the abnormal cloned piglets. The altered DNA methylation mainly affected the low and silently expressed genes. There were differences in both pathways and genes, such as the MAPK signalling pathway, the hypertrophic cardiomyopathy pathway, and the imprinted gene PLAGL1; all of which may play important roles in development of the abnormal phenotype. CONCLUSIONS: The abnormal cloned piglets showed substantial changes both in the DNAm and the gene expression. Our data may provide new insights into understanding the molecular mechanisms of the reprogramming of genetic information in cloned animals.
