The book of life

Scientists still don’t agree on whether it is useful to keep on stimulating the brain also at advanced age. This has to do with the fact that our body is formed not only by what we do, what we eat and what kind of substances we come into contact with, but also by the inherited matter that came with us at birth and from which we are made. We can’t change this heritage, our genes, but we can influence it.

d_10_m_lan_1bThe cells in our body are small in size, but huge in complexity. It is very hard to imagine that one cell contains not only several machineries to survive and function, but also our complete package of hereditary information. Every cell in our body, except the red blood cells, carries in its nucleus a copy of two complete sets of the human genome spread out on 23 pairs of chromosomes. One set comes from our father and the other one from our mother. Just think, all this arises from that one sperm cell of father and that one egg cell of mother, having merged and being copied over and over again!

A chromosome is made up of one very long DNA molecule wrapped in proteins. Different parts of DNA have different tasks, some of which are not known yet. The segments of DNA that contain hereditary information are called genes. Many genes can fit along the ladder of a single DNA molecule. The human genome comprises around 20.000 genes, according to the latest view among scientists worldwide.

Recipes
Genes hold the information necessary to build and maintain cells. Depending on the place in the body where the cell finds itself, different genes from the genome are active. Genes know the recipes for making proteins. Whenever a gene is operational it results in the production of certain proteins. Almost everything in our body is made out of or by proteins, from every hair on our head to the hormones that make us interested in sex.

Genes hold the recipes to make proteins. (© Alila Medical Media - Fotolia.com)

Genes hold the recipes to make proteins. (© Alila Medical Media – Fotolia.com)

The genes we all possess can be compared with a book. Everybody has their own, unique book of life. Half of the chapters in it are written by your father, the other half by your mother. During your development in the womb, your book is being read and this way you come into being: with the blue eyes of your father for instance and your mother’s blond hair.

Actually, I should be using the word allele in this aspect. Genes hold basic instructions. They are the same for everyone. But one gene can exist in a number of forms. These variants are called alleles. For example, a certain gene is involved in hair colour. You carry variants of this gene, alleles, and they determine whether you get blond, red, brown, or black hair. Since everybody uses the word genes, I will continue to do so as well, but as long as you know the name of the individual variants of genes is in fact allele.

Errors
No book is perfect. All books of life contain typographical errors. This can cause something to go wrong while your book is being read. These errors in the genome are responsible for instance for the birth of a child with Down syndrome, or spina bifida, or cleft lip.

At the moment of your birth, the book has by no means been finished. During your whole life, the reading will continue. Which chapter will be read depends on what you are doing, with what kind of substances you come into contact, what you eat.

To put it more biologically correct: genes are being switched on and off. Specific molecules in the body send signals to genes to become operational or to shut down. This is a dynamical process that is strongly influenced by the environment.

When a chapter with a defective text is being read, something can go wrong and you could end up getting a disease. Only a few diseases are known though, which arise from an error in only one gene. In general, several genes with erroneous texts have to be switched on for a disease to develop.

“The genome is not a blueprint for constructing a body; it is a recipe for baking a body.”
Matt Ridley, science writer

In the whole world, scientists are busy finding out which defective genes are involved in which diseases. In most cases, it is terribly difficult to discover a direct link between specific genes and particular biological processes or diseases. Often complicated mechanisms are going on, in which different genes play a role.

Manipulation
The next step of course would be to correct errors. Manipulating defective genes is only possible via highly elaborate gene therapies. In the future, defective genes could perhaps be repaired this way or they could be replaced by new, healthy genes.

It would be nice if we would have the possibility to repair defective genes. (© freshidea - Fotolia.com)

It would be a big step ahead if we would have the possibility to repair defective genes. (© freshidea – Fotolia.com)

In laboratory animals, genetic manipulation is employed extensively already, but for human beings no successful treatments are available yet. Actually, we don’t fully know thus far what will be the consequences of what we are doing where genetic manipulation is concerned. Interfering in such a complex process brings about huge risks.

So, it is important not to rely too much upon the fact that soon methods will become available to tinker with your genes. As far as genes are concerned for the time being, preventing is the only option. That being so, it is wise to take matters in your own hands and make sure your gene collection stays as healthy as possible. Therefore, you have to try to live in a way that will skip certain unhealthy chapters in your book of life.

By sticking to a healthy lifestyle you can exert a lot of influence on whether or not genes will be activated. It certainly is not true that you find yourself at the mercy of the genes with which you were born. Genes are important as they contain the directions for the initial development of the brain, but they are not determinative since they don’t control how the brain will respond. Everything we do affects everything that follows. From conception to death, our genes and the environment interact to continually change our brain.

Images

The book of life © red150770 – Fotolia.com
Cell drawing – The Brain from top to bottom
Chromosome © zerotwolab – Fotolia.com

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