Tuesday, December 22, 2015

Epigenetics: Under the Surface

What lies under the surface? The external and internal structure and function of the human body is complex and beautiful beyond belief. According to what master plan is the human body assembled? We could devote a lifetime of study even to scratch the surface of knowledge about molecular biology. Still, our knowledge of epigenetics is in its early stages.

A few decades ago basic knowledge of genomics—the science of structure, function, and mapping of DNA—was sufficient to satisfy most laypersons’ curiosity about heritable human characteristics. In recent decades our knowledge extends far beyond DNA with its code for protein production. In particular, we speak of the astonishing phenomenon of reproduction—the assembly of DNA-produced protein substances during prenatal body development. Genomics reveals but a small portion of the complex story of reproduction of a unique new life. Epigenetics is the new buzz-word. 

At the risk of trivializing a majestic biological process with a mundane analogy, we illustrate with a culinary example. When a chef prepares a gourmet dish, all prescribed ingredients must be initially assembled. More important is the activity to follow: (1) adherence to a coherent recipe (2) use of correct utensils (3) appropriate procedure (4) proper control of necessary factors such as temperature, and (5) maintaining favorable conditions when the project is complete. We see that in addition to the initial assembly of appropriate ingredients, far more is involved in a successful gourmet production.

We transition to prenatal production of a new life—admittedly a giant leap. One important term is “gene expression.” Acquiring the biological components of the human body proteins is the initial step. But fabrication of the components is ultimately more important. The latter is a topic under the heading of epigenomics. How does the assembly process unfold? Life scientists define gene expression as the process by which information from a gene is used in the synthesis of a functional gene product. Production of a complex, unique new human life in the womb is a creative process far beyond our imagination. Gene regulation insures that genes function to produce specific cells at the proper time.

Let us consider a few molecular wonders of the reproductive process. We quote from opening statements of a lengthy Quiagen website. “It is known these non-genetic alterations are tightly regulated by two major epigenetic modifications: chemical modifications to the cytosine residues of DNA (DNA methylation) and histone proteins associated with DNA (histone modifications.)” The Quiagen site continues, “Epigenetics is one of the fastest-growing areas of science and has now become a central issue in biological studies of development and disease.”

For the remaining space in this post we discuss methylation. DNA methylation describes the addition of a methyl group containing one carbon and three hydrogen atoms. This molecule attaches to one of the nucleotides of the DNA molecule—namely, cytosine. In our previous references to the base pairs in DNA which code for proteins, CG is one of the “alphabetic letters” of the DNA protein coding scheme, along with AT. C abbreviates cytosine. The methylation of DNA may occur owing to environmental conditions. Or, it may occur as a result of naturally occurring cell processes. Whatever the cause of methylation, it may result in developmental advantages during the process of body formation during reproduction. Methylation is a disadvantage if it results in a disease state. The methylation process is heritable, even if it results from environmental factors.

Methylation of DNA is important during the many stages of fetal development in which some processes are turned on while other processes are turned off. These findings are important as they provide insight into regulatory elements guiding tissue specification that lead eventually to organ functionality.

Bioscientists are working to unlock more secrets of epigenetics. We believe that in our lifetime many more wonderful truths concerning knowledge of life processes, physical wellness, and healing will be discovered. Of the hundreds of written sources dealing with epigenetics, many state that the processes arising during fetal development are still largely unknown. 

Many personal questions concerning wonders of life are hidden with the Creator of all things. King David celebrates the omniscience of God in his majestic Psalm 139:13-16:

For you created my inmost being: you knit me together in my mother’s womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well. My frame was not hidden from you when I was made in the secret place. When I was woven together in the depths of the earth, your eyes saw my unformed body. All the days ordained for me were written in your book before one of them came to be.