Principles of 3-D genome folding and gene expression studied across species – Phys.Org

March 7, 2017 The evolution of globin gene domain 3-D organization exhibits a tendency to the formation of globular structures. Embryonic and adult globin genes are designated with light grey and dark grey circles, respectively. The major regulatory element (MRE) of the Danio rerio major globin gene locus and -globin gene domains of warm-blooded vertebrates is designated with red hexagon. The locus control region (LCR) of the -globin gene domains of warm-blooded vertebrates is designated with a set of red rectangles. Experimentally validated insulators and putative ones are designated with dark blue ellipses and light blue ellipses, respectively. The spatial configuration of the mouse -globin gene domain and the interaction frequency between the insulators in the chicken -globin gene domain in embryonic erythroid cells before globin expression switching are currently unknown. Credit: Razin lab

It seems like a feat of magic. Human DNA, if stretched out into one, long spaghetti-like strand, would measure 2 meters (six feet) long. And yet, all of our DNA is compacted more than 10,000 times to fit inside a single cell. How is this accomplished while preserving the overall, vital genomic organization?

With new techniques, scientists are beginning to understand the principles of 3-D genome folding. And in one of the studies of its kind, Anastasia Kovina, Sergey Razin a et al. have examined the well-studied globin gene cluster to understand the evolution of genome folding behind a vital process, delivering oxygen throughout the body.

Their study sheds light on the genomic evolutionary process that resulted in segregation of the alpha and beta-globin genes into two differently regulated domains in warm-blooded vertebrates. "We suggest that globin gene domains of some modern, cold-blooded animals retain certain features of an ancient, ancestral domain," said corresponding author Sergey Razin.

By investigating globin genes in the zebrafish model organism, their evidence points toward their suggestion that modern clusters of - and -globin genes of warm-blooded animals evolved from an ancestral locus, contained within a globular genomic cluster that was located close to other evolutionary conserved genes.

They found that evidence of a dynamic genomic organization of globin gene cluster that differs depending on the developmental age of the zebrafish. Using different assays, they have shown that the adult globin sub-compartment of the zebrafish gene locus is insulated from the embryonic larval component.

"We have found that the major globin gene locus of zebrafish (Danio rerio) is structurally and functionally segregated into two spatially distinct subloci harboring either adult or embryo-larval globin genes," said Razin. "These subloci demonstrate different organization at the level of chromatin domains and different modes of spatial organization, which appears to be due to selective interaction of the upstream gene enhancer with the sublocus harboring globin genes of the adult type."

This organization drastically differs from that of the mammalian - and -globin gene domains, where both embryo-fetal and adult globin genes are recruited to the same regulatory elements in a developmental and stage-specific process.

The finding of a functional separation of adult and embryo globin genes reflected in the 3-D genomic organization chromatin will provide an important contribution to the field and interesting evolutionary perspective to how gene clusters are organized and expressed.

Explore further: Researchers find potential treatments for hemoglobinopathies

More information: Evolution of the genome 3D organization: comparison of fused and segregated globin gene clusters, Molecular Biology and Evolution (2017).

An article published in Experimental Biology and Medicine (Volume 242, Issue 3, February, 2017) identifies microRNAs (miRNAs) as key factors in some hemoglobinopathies, genetic disorders characterized by alterations in the ...

Promising results from the first clinical trials of globin gene transfer to treat beta-thalassemias-inherited forms of anemia-have eliminated the need for blood transfusions in some individuals. Enhancing current gene therapy ...

Scientists at Karolinska Institutet in collaboration with Estonian Competence Centre on Health Technologies have developed a new gene expression analysis method to widen the usage of blood in biomarker discovery and analysis. ...

In biology, free radicals are often regarded as the source of all evil and the major cause of molecular damage and aging. However, free radicals are indispensable as signaling molecules governing important functions in the ...

Genetic mutations that affect our blood cells' haemoglobin are the most common of all mutations. It has been estimated that around 5% of the world's population carry a defective globin gene.

UCLA stem cell researchers have shown that a novel stem cell gene therapy method could lead to a one-time, lasting treatment for sickle cell diseasethe nation's most common inherited blood disorder.

It seems like a feat of magic. Human DNA, if stretched out into one, long spaghetti-like strand, would measure 2 meters (six feet) long. And yet, all of our DNA is compacted more than 10,000 times to fit inside a single cell. ...

Scientists are beginning to realize that many cellular behaviors, such as metastasizing cancer cells moving through the body or wound healing, aren't random events, but the result of coordinated actions by cells.

Scientists at Baylor College of Medicine, the Lawrence Berkeley National Laboratory, Massachusetts Institute of Technology and Purdue University have completed a model of unprecedented near-atomic resolution of the chemical ...

Black swan events are rare and surprising occurrences that happen without notice and often wreak havoc on society. The metaphor has been used to describe banking collapses, devastating earthquakes and other major surprises ...

The speed at which a tiny ant evolves to cope to its warming city environment suggests that some species may evolve quickly enough to survive, or even thrive, in the warmer temperatures found within cities, according to a ...

While there are already a number of species named after famous British broadcaster and naturalist Sir David Attenborough, including mammals, reptiles, invertebrates and plants, both extinct and extant, not until now has the ...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Read more from the original source:
Principles of 3-D genome folding and gene expression studied across species - Phys.Org