Genetics vs epigenetics: gene alterations to gene expression.

Genetics vs Epigenetics: From Gene Alterations to Gene Expression

“Genetics usually comprises the study of genes and related alterations while epigenetics comprises the study of gene expression and proteins involved in the process. Let’s check out a few important differences between genetics vs Epigenetics.” 


Genes are always blamed for causing genetic diseases. Inherited gene mutations can be transmitted to consecutive generations and spread the disease. So genetic changes are lethal, impactful and inherited. 

Recent studies suggest that environmental factors also have a significant role in perceiving and/or deceiving health conditions, which are epigenetic changes. Such factors are diet, exercise, mindset and any environment where the person lives. 

These factors interact with our genetics and produce abnormalities which are categorized as epigenetic modifications. 

Meaning both nature (genetics) and nurture (epigenetics) have a pivotal impact on organisms’ life. Genetic studies genes, mutations and inheritance while epigenetic studies gene expression, associated mechanisms and environmental factors. 

Both fields are now important to study a disease where a disease potentially occurred by any gene(s) mutations while those mutations occurred by the influence of epigenetic factors, likely. However, epigenetics and genetics both transmit genetic information from one to another generation. 

In this article, we will try to understand the concept of genetics and epigenetics and how both are different. I will explain several key differences to strengthen the depth of the topic. 

Related article: Difference Between Genetics Vs Genomics.

Stay tuned. 

Genetics vs Epigenetics 

Genetics is a study of heritable gene alterations while epigenetics is a study of gene expression. William Bateson coined the term, “Genetics” while Conrad Waddington first introduced the term, “epigenetics.”

Let’s start with an experiment. 

Srinivasan T (2011) in her paper explained one experiment on mice. They noticed that mice susceptible to cardiac and diabetic disorders can also produce healthy progenies if an adequate and healthy diet and other conditions are provided. She further stated,

“Genetic factors can be overridden by epigenetic factors.” 

-Srinivasan T, 2011

Meaning: 

The word “Genetics” came from the Greek word “Genetikos” which means the study of heredity. On the other hand, the word “epigenetics” is made up of two words ‘epi’ which means ‘above’ and ‘genetics’ which means ‘hereditary studies.’ 

So epigenetics literally means beyond or above genetics. 

Definition:

Genetics is a field of biology that studies DNA, genes, mutations and the inheritance of traits. 

Epigenetics is an interdisciplinary field of genetics that studies gene expression (without change to the underlying sequence), protein-DNA interaction and its impact on gene regulation.   

Congenital vs lifestyle: 

Genetic changes are congenital and occur by birth while epigenetic changes are caused by lifestyle factors. Hence genetic diseases can’t be repaired while epigenetic alterations can be managed by adopting a healthy lifestyle. 

Quality vs Quantity: 

This point is important to understand the present comparison. 

DNA replicates and becomes double, transcribe and translate to produce a protein. When any mutation occurs in a gene, either a truncated, partial or fully abnormal protein forms. Oftentimes, genes miss the sense to produce a protein. Thus genetic changes have a direct impact on the “quality” of the protein.  

Post-transcriptional and post-translational modification has a significant role in weaving the epigenetic profile for a gene. Alteration at this level may directly impact the amount of protein produced. Meaning, the “quantity” of the protein. So underproduction of normal protein and overproduction of abnormal protein creates a problem. 

Mechanisms: 

Another point coming out of the previous point is the mechanisms involved in each. Replication, transcription and translation are common mechanisms for a gene and are covered in genetics. Conversely, post-transcriptional and post-translational mechanisms such as methylation, acetylation, ubiquitination, histone modifications, hydrolysis and chromatin remodeling are mechanisms commonly covered in epigenetics. 

Take a look at the comparisons.

Genetic mechanisms Epigenetic mechanisms 
Cell division Methylation
Cell metabolismAcetylation
Replication Histone modifications
Transcription Ubiquitination
Translation Phosphorylation
DNA repair Glycosylation
Recombination Hydroxylation
Non-homologous end joining Deamination 
Direct DNA repairPrenylation
Proteolysis 
Chromatin remodeling

Inheritance: 

The genetic information of an organism inherits from one to another generation and so are any genetic changes too (Both chromosomal and DNA mutations). Intriguingly, it remains unchanged throughout the life of an organism. 

Contrary, though epigenetic changes are inherited too, can be changed and managed because it’s more flexible and subjected to change. External environmental factors, deity, unhealthy habits, stress, toxin and mutagen exposure are factors that influence the epigenetic profile. 

Mutagens and mutations: 

Traits governed by genetics are subjected to mutations- any sudden change in the structure of DNA. Deletion, duplication, translocation, copy number variation or abnormal repeat expansion when occurs in DNA, it alters how the protein forms and eventually causes disease. 

Traits governed by epigenetics are influenced by euchromatin and heterochromatin conversion. For example, the addition of a methyl group to DNA blocks the site for enzymes to synthesize the gene and eventually makes the gene silent. 

Illustration of epigenetics.
Illustration of epigenetic factors and. changes.

Factors: 

Genetic factors are abnormal cell division, mutagens, teratogens or abnormal metabolic activities while epigenetic factors are surroundings, temperature, diet, exposure to toxins, stress, unhealthy habits and unbalanced lifestyle. 

Reversibility: 

We can’t determine what and how a cell divides or how a fetus develops during the developmental stage; that’s totally a random process. Once any change occurs at a DNA sequence level, it remains as well. Genetic changes are non-reversible. 

Once it occurs it will remain, until the organism dies. 

On the other side, epigenetic changes are manageable as well as reversible too. We can manage our diet, change our habits, change our unhealthy surroundings and thus can repair any epigenetic alterations. So epigenetic changes are reversible. 

We can reverse the condition. Trigger the production of healthy protein and reduce the product of unhealthy protein. 

Effect:

“Genetic changes are like a slow poison.”   

Intriguingly, any lethal genetic changes occur less frequently and oftentimes are repaired by the cell’s natural DNA repair mechanism. But once it occurs, it transmits, one to another and eventually into the entire population, slowly and steadily.   

Epigenetic alterations are rapid and restricted. If it occurs in a person, it will remain restricted to an affected person only, unless it undergoes germ cells. It can’t spread to the entire population. 

Genetic changes Epigenetic changes 
Slow Rapid 
Spread to the population Can’t spread
Spread to other organisms Restricted to only affected individual 

Stability: 

Genetic changes are highly stable, as we explained and thus took part in the process of evolution and development of new genotypes, phenotypes and traits. On the other side, epigenetic changes are highly unstable. It produces a temporary effect but if remained untreated can be settled.  

Study techniques:

PCR, DNA sequencing, restriction digestion and microarrays are some techniques commonly used for genetic studies. While methylation-specific PCR, Chi-Seq and methylation sequencing are techniques that study various epigenetic alterations.

Illustration of genetics.
Illustration of genetic factors and changes.

Cancer: Genetics and epigenetics 

It’s intriguing to discuss cancer in terms of epigenetics and genetics because it nullifies all the possibilities as cancer itself is an uncontrolled process. 

In cancer, genetic changes may occur in a gene or DNA after birth or during the entire life of an individual and remain non-inherited. While epigenetic changes may occur during the congenital or developmental stage cause cancer and remain stable. 

This means non-inherited cancers can be caused by either genetic, epigenetic alterations, or both. So when talking about cancer this general boundary that we just have made to distinguish genetics vs epigenetics dissolves.

What we have, so far, discussed is subjected to a general understanding of the individual topic.  

Wrapping up: 

Unwrapping the previous belief that only genetic factors can have an impact on cellular activities. The new and updated knowledge suggests that other factors have a significant impact on cellular activities and the life of an organism– for example, epigenetics.

This means nature and nurture both control cellular activities and organisms’ life. Nonetheless, Genetic alterations that cause thalassemia, Huntington’s disease, breast cancer or Down syndrome still can’t be reversed. Notedly, conditions like thalassemia and breast cancer, with the use of modern technology are manageable. 

This article will perhaps clear your doubts about genetics vs epigenetics. I hope you like this article. If I miss any point, please comment. Till then, do bookmark this page and share this article.  

Sources: 

Srinivasan, Thaiyar M. “Genetics, epigenetics, and pregenetics.” International journal of yoga vol. 4,2 (2011): 47-8. doi:10.4103/0973-6131.85484. 

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