Epigenetics and Phenotype
By: Jim Virkler
Epigenetics is a new and unfamiliar term to many non-scientists. The term signifies inherited changes to the phenotype (physical and behavioral traits) that are not caused by the genetic code of DNA. To bioscientists knowledge of epigenetics opens new medical knowledge to enhance human health and longevity. It is the next step in the lexical sequence—genomics, proteomics, and epigenetics.
Most laypersons are familiar with the term genomics. They know that most physical traits result from DNA inheritance. Knowledge of another field, proteomics, has spun off from genomics. The human DNA code is responsible for building physical traits by its ability to produce proteins, the building blocks of our physical bodies. Proteomics is a specialized knowledge of the composition, structure, and multiple functional roles of proteins.
We focus on two other related terms which have become part of our biological lexicon: genotype and phenotype. Our genotype is our personal genetic sequence of heritable genes making up our DNA. It provides the code for the manufacture of multiple proteins which compose our physical body. It is not dependent on any environmental factors. Personal genotypes are intrinsic to one individual.
A phenotype, in contrast, is observed as outward, physical traits. It could be influenced by environmental factors other than our DNA sequence. Unique traits and personal behavior are also considered part of our phenotype. We may see that phenotypes are dependent on genotypes to a large degree. For example, physical size and other traits such as hair and eye color trace to our genotype.
Explanation of the human architectural body plan is not simply a matter of understanding the function of DNA in inheritance. This basis of inheritance is exceedingly important, but with the passage of time we have become aware of the wonder and complexity of other factors—epigenetic factors which govern the engineering of body plans. We introduce another term in our biological lexicon. It is termed developmental biology. Epigenetics may be linked with developmental biology to create developmental epigenetics.
We introduce new vocabulary to help us focus on the cutting edge in developmental biology. Several new expressions may trigger expanded reader interest in this field: gene expression, gene regulation, cellular differentiation, and morphogenesis. All terms hold the potential for future post topics.
Our family has become aware once more of the miracle of developmental biology in a short nine months. A new grandson has joined his two-year-old brother and four-year old sister in another manifestation of the developmental wonders of the creation of a new life in less than one year. Our family has termed the event a “divine developmental miracle.”
The arrival of a new grandson inspired your blogger to create a series of posts on our family version of “developmental biology” in 2013. I link one of many posts from that sequence. You may also click on the previous four posts (older post) or the seven posts to follow (newer post).
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Jim Virkler, a retired New Jersey public school science educator, now devotes his time investigating the harmony of scientific discoveries and Christian faith. He and his wife, Eleanor, now reside in the mid-west near their children and grandchildren.