Epigenetic modifications in health and disease

Although for most genes we inherit one copy from our mother and one from our father, this is not the case for imprinted genes. Depending on the gene, either the maternal or the paternal gene gets silenced through chromosomal methylation.

Genomic imprinting takes place during gamete formation and has a central role in development as it ensures mono-allelic gene expression. Failure to maintain or erase these epigenetic marks results in gene dosage dysregulation and gives rise to specific human diseases, known as imprinting disorders.

Scientists on the EU-funded INGENIUM project have set out to provide fundamental knowledge into the origin of parental-specific gene expression and its role in embryogenesis. To achieve this, they are using state-of-the-art technologies to study the epigenome and especially identify the 5-methyl-cytosine marks on the genome. Combined with functional gain of function and loss of function studies, this information will provide insight into the mechanism of epigenetic reprogramming early during development.

In addition, the consortium aims to investigate the role of histone modifications in genomic imprinting and the mechanisms underlying its regulation. For this purpose they have chosen specific imprinted loci and will examine how genomic imprinting is affected by mutations in histone methyltransferases and demethylases.

To extend their findings into imprinting disorders, researchers have recruited large cohorts of patients affected by Beckwith–Wiedemann syndrome and Silver–Russell syndrome. Both of these diseases are associated with chromosome 11 imprinted genes, and to facilitate their investigation researchers have recapitulated the mutations in mouse models. Given the importance of imprinted genes in stem cell differentiation, the consortium also plans to correlate gene expression and epigenetic modifications during experimental somatic cell reprogramming.

Taken together, INGENIUM activities will provide fundamental knowledge on the role of chromatin dynamics in gene expression. Project findings could be extended to explain the aetiology of various diseases.