The Nucleobases Etymology

Albrecht Kossel (left) and a thymus histological section (right)

Adenine, thymine, cytosine and guanine are nucleobases used in forming nucleotides of the nucleic acids. The purine nucleobases (A and G) bind to the pirimidinic ones (C and T) via hidrogen bonds in the DNA. 

Albrecht Kossel (1953-1927), was a German biochemist who isolated and described the nucleobases and named them with the names we currently use.

Identical or fraternal twins?

They are so similar... but are they really the same? Today we are going to speak about the difference between identical and fraternal twins.

First of all, a twin is one of two offspring in the same pregnancy. The main difference between identical and fraternal twins is that identical twins come from the same zygote that is divided in two different embryos, and fraternal twins come from two different zygotes fertilized by two different sperm cells.

Twin differences. Picture from www.genomesunzipper.org

Ok, until now it seems easy, more or less. But in real life, what can make us differentiate between both types of twins? Here some clues:

Milk and Humans

Hello fellow! Back again with a genetic curiosity. Today, milk will be the main character.

From the beginning, humans and milk have been very related. In addition to the appropriate amounts of carbohydrate, protein and fat, breast milk also provides vitamins, minerals, digestive enzymes and hormones. All what is needed by babies.

Picture from www.myspaceantics.com

About cloning...

I am sure that all of you have heard about cloning before. Despite of being a scientific invention or discovery, it has existed from long time ago in nature. It is also called asexual reproduction. It happens, for example, in bacteria. But it also happens in higher animals. 

Example of fragmentation in a starfish. Picture from blocs.xtec.cat

Cloning is an identical copy of an individual, organism or cell that already exists. 

But coming back to more human concepts, cloning has been one of the most interesting issues in science since the discovery of the DNA. The idea of creating a new individual with exactly the same genome as another... it almost means immortality. But we can discuss about philosophical meanings later.

Picture from www.neatoshop.com

Genetic engineering

What do we think when we hear “genetic engineering”? I was used to think in fluorescent animals, giant vegetables and the Ninja Turtles (I haven’t lost hope). But I was pretty surprised when I discover the real meaning.

As a definition, genetic engineering is the modification/manipulation of an organism genome using different molecular techniques. From that definition, we should go further and think what it really means. We may travel to the 1970’s to see that the first organisms genetically modified were viruses and bacteria. The main aim of these projects, after the great discoveries about the existence and the structure of the DNA, was to know if this DNA was modifiable and if life could survive to these modifications. The process is theoretically simple: we take or create a DNA sequence that we know encodes for a particular gene or group of genes, and we introduce this sequence inside the host cell.

Dolly the sheep. The process of cloning. Picture from www.glogster.com

Slight differences

Let's start with general genetics: "What is DNA and what is for?" and "How could we be apparently so different among us but at the same time the same species?"

For answering the first question we will start with the Central Dogma of Molecular Biology:

The DNA is our particular library, essential for life. We have all the necessary information encoded in a combination of four nucleotides (A, T, G and C). This library has hundreds of books, which we are going to call RNA. We have a lot of different kinds of RNA, which maybe is boring and not what you are looking for at this blog. So let's say that this RNA should be translated into proteins to be useful for a cell. These proteins will work independently or as a subunit of a big complex to make what is required.

Once upon a time

Welcome, ladies and gentlemen, to the world of science!

I am pleased to announce you the beggining of this blog: Genetics and Beyond. I would like to show everyone all different aspects of Genetics and Biology that are usually encoded under technical words quite difficult to understand. I will try to answer questions like: what is Genetic Engineering and what could it do for us? Is it ethic to manipulate gens? Why endogamy is so bad for a species? What determine our eyes colour? Is it everything inheritable? Which advantages has infidelity for animal survival and evolution?

Also, I would like to explore the history of Genetics througout the most important personalities of this world and explain some of the diseases that are affecting human beings.

Science is part of the XXIst century culture, so prepare yourself, take a seat, and enjoy. Future is already here -and has been here for thousand years-.