Imprinted genes: important regulators in development.

The imprinted genes are characterized for their allele-specific expression, which present a unique phenomenon in the epigenetic and developmental studies. The field had dramatically progress in terms of establishment, maintainance and function of imprinted genes in organ development. The imprinting was primarily discovered in neuro-transplantation studies, and thereafter focused on a few well-known imprinted cluster. With increasing application of omics techniques, more imprinted genes were screened and identified, which drawn great attentions and discussions by scientists in the field. One of wonderful example is peculiars extrapolation and debate of evolutional conservation of imprinted genes based on the data analysis of the whole genome DNA methylome and histone modification. In this review, the current research of imprinted genes in mammals were summarized from the feature of the genes, the roles in development, the mechanism of regulation, the advances of research methods, the evolution of parental relationship and the interaction between imprinted genes and environmental factors. This review will be helpful for general understanding and research approach of imprinted genes.