A work published in the magazineCell Reportsdescribes with great precision thegenomic regulation mapand offers new keys to understand the differences between animal species and even the development of some diseases. The study, led by researchers from the Carlos III National Center for Cardiovascular Research (Madrid), describes the interaction of five proteins of the Hox system, essential for the development of the embryo.
How is it possible that humans and insects are so different if our genome is very similar? The latest advances in genetics are solving this question, and the key lies in the way each species regulates the function of its genes. During embryonic development, various processes take place that lead, from a single cell, to theformation of an independent being with all its organs and systems working in a coordinated way. By successive divisions, the zygote or first cell resulting from fertilization gives way to numerous cells that are organized in space and, depending on their position in the embryo, activate some groups of genes or others to form specialized tissues.
In this process of specialization, the genetic system of theHox proteins and their cofactors, which allow to establish the orientation of the head-tail axis and the places of formation of the different organs. In the new study, scientists have analyzed thousands of regions of the genome where the cofactors of Hox proteins bind. “This work provides for the first time a complete catalog of the regions of the genome regulated by Hox proteins and will allow us to understand how cell diversity is generated and its organization in tissues and organs correctly”, explained Daniel Mateos, one of the authors .
The work has shown that, despite the fact that the genome of mammals is similar to that of other animal groups such as insects, it shows a much greater complexity in its functions. Specifically, it has been found that the homeoproteins of the TALE type Meis1, Meis2, Prep1, Prep2 and Pbx1, which until now were thought to function in a similar way to those of insects, have other independent Hox functions, and could have a in the development of tumors. For example, while Meis1 activates cancer, Prep1 inhibits it. These studies can therefore help to identify the molecular mechanisms responsible for tumor formation. “The study has also allowed the detailed description of the small sequences of DNA” words “that these proteins select from the approximately 3 billion” letters “that our genome contains,” explained Miguel Torres, coordinator of the work. “These advances will allow us to understand how the different Hox select their target genes , and thus deepen their biological function, both under normal and pathological conditions”, he concluded.
