Environment Genetics Psychology

Global Debate: What affects behaviour Genes or the Environment?

Written by Fouzia Sadiq

Does “DNA (genes) control you?” Or is it the environment? Your internal gene pool is not only just DNA that was inherited from your elders but it’s a combination of your inherited material but also a daily dose of your external environment. Most of your genes switch on or off with the aid of external stimuli, which is how your 725 Mb genetic setup influenced by your own surroundings. Today we will talk about some ways how your genetic setup is influenced by the relative external environment.

Transcription factors – Environmental Pollutants can affect the DNA sequence by changing the transcription factors, which play an important role for initiation of central dogma to express respective gene. During transcription these factors have DNA binding sites attached to DNA sequence and in turn control other proteins activity to derive gene expression. Thus, if an external event triggers these signals, their response may also vary leading to up regulation or down regulation of gene expression.

For example, these pollutants indirectly cause oxidative stress that influences NF-kB, the well-studied transcriptional factor that can leads to different kinds of cancers

Gene-gene interactions – Here is another way, when your surrounding environment affects the interactions of genes with one another by indirectly contributing to hinder the gene expression. For example, depression is caused by regular drinking of alcohol. It is due to low folate levels which in turn controls by (TACE) a specific gene, not to help another gene (MTHFR) make enough of its protein.  Too little of this protein changes the level of folate (another protein) in our blood, and this may cause depression.

Chemicals – Some chemicals are also not good for your health even many of these may change your DNA sequence permanently so can be heritable. Same way there are certain chemicals which affect gene expression involved at the time of development. Cyclops fish are a well-studied example of the way in which an environmental chemical MgCl2 can affect expression of genes involved in eye development

 Temperature – In some organisms outside weather may also influence their own running genetic channel. This may also modulate gene expression in certain organisms. For example C gene carries by Himalayan rabbits, which have role in development of pigments in the fur and eyes, and whose expression is regulated by temperature.

 Nutrition – It is a very interesting fact that your dietary supplement also triggers your genetic conditions. Pregnant woman’s diet determines the health of her offspring. The folic acid supplement to the pregnant women takes care of the proper development of the fetus. Similarly drugs intake can also lead to fetal abnormalities by switching on or off certain genes.

 Viral proteins – Certain oncogenic viral proteins from (cancer-causing) viruses, including adenovirus, SV40, and human papillomavirus, were found to alter the tumor suppressor protein called retinoblastoma (Rb). It plays an important role in cell proliferation by keeping the cell cycle regulation in check.


 Mutagens –They may act directly on the DNA, causing direct damage to the DNA, and most often result in replication error, or mutations. Here how tobacco intake effect your genetic constituents by conferring transversion mutations. p53 is a tumor suppressor gene, mutations in this are frequent in tobacco-related cancers altering cell cycle checkpoints at multiple stages. In lung cancers, the p53 mutations are significant between smokers and nonsmokers.

So it’s not merely “DNA which controls you” but your DNA listening to your environment, your surroundings, your way of living and even your daily habits and that controls your DNA. Our DNA luckily has a lot of space where a bit of damage is not panic or it could be repaired. But some of these persistent signals which alter your DNA sequence permanently may also transfer to your next generation.  What if it happened? So take care of your surroundings and it would eventually take care of you and your generations



About the author

Fouzia Sadiq

Meet Fouzia, M.phil in Molecular Biology. Her research was based on human molecular genetics from Quaid e Azam University, Pakistan. Currently, she is Lecturer in Women University in Azad Jammu Kashmir. She also loves to explore nature.