Globin genes transcriptional switching, chromatin structure and linked lessons to epigenetics in cancer: A comparative overview

At the present time research situates differential regulation of gene expression in an increasingly complex scenario based on interplay between genetic and epigenetic information networks, which need to be highly coordinated. Here we describe in a comparative way relevant concepts and models derived from studies on the chicken α- and β-globin group of genes. We discuss models for globin switching and mechanisms for coordinated transcriptional activation. A comparative overview of globin genes chromatin structure, based on their genomic domain organization and epigenetic components is presented. We argue that the results of those studies and their integrative interpretation may contribute to our understanding of epigenetic abnormalities, from β-thalassemias to human cancer. Finally we discuss the interdependency of genetic–epigenetic components and the need of their mutual consideration in order to visualize the regulation of gene expression in a more natural context and consequently better understand cell differentiation, development and cancer.