Epigenetic effects of trisomy 16 in human placenta.

The methylation profiles of the placental tissues of human embryos with normal karyotype and trisomy 16 were compared using an Infinium HumanMethylation27 BeadChip array (Illumina, United States). Numerous differences between the extraembryonic tissues with diploid and aneuploid karyotypes were observed. The extraembryonic mesoderm of embryos with trisomy 16 appeared to be less methylated than the diploid tissue, whereas the cytotrophoblast of aneuploid embryos was hypermethylated. The presence of the supernumerary chromosome was shown to influence the epigenetic profile of the genome by changing the level of methylation of CpG sites of all chromosomes. However, the largest number of differentially methylated loci was found on chromosome 16. Furthermore, more often, the epimutations were tissuespecific. In both tissues, the hypomethylated genes belong to the groups of genes responsible for different metabolic processes, whereas the hypermethylated genes control the processes of development, cell adhesion, immune response, and response to stimulus. [ABSTRACT FROM AUTHOR]