Genetic networks

From my other blog, Bacterias Electrónicas 

We all know that humans, and every other living being, are made out of cells. Some beings are actually only one of these. What most people don't know so well is what is inside these 'cells'. DNA, right? But, what else is in there?


Some of you will know there are things called organelles, which in a way are like our organs at an intracellular scale. If you know about them, I'm sorry but that's not what we will be talking about here. Today we are interested in proteins. These macromolecules, composed of thousands to millions of atoms (which is a very small amount, despite what it may seem), do all the lowest-level functions inside a cell. They are the workers of the cell factory, so to speak.


Each protein has certain functions, and there are a lot of them. If you want a graphic example, a particular protein may have a part (or domain) that sticks out of the cells and is able to attach to the outside medium. Whenever the cell needs it, all the proteins of this kind will activate and accomplish this function.


There is also the idea that DNA regulates about anything. How does it do it? Well, through proteins! What genes encode are the different proteins, which the cellular machinery (more proteins!) read, transcribe and translate to arrive to the functional form of the protein. But there's a lot of proteins, and we can't have all of them at once! Furthermore, proteins are stupid and they may do their function even when it's against the cell's interests. Due to this, they are produced depending on the needs of the moment. But, how does the protein factory know which ones are needed at each time?


As we said, proteins do everything, including regulating the production of other proteins. Every protein affects, directly or indirectly, production and function of other proteins (they also active and deactivate other proteins that have already been translated). In this way, there can be joint responses to certain events, signals or necessities by groups of different proteins. Since every organism has millions of different proteins and thousands of necessities to solve, this generates a very complex network in which everything is connected. This, and its parts, are genetic networks (don't forget that DNA is at the basis of all this).


Experimental geneticists eliminate different elements (specific proteins) of this network one at a time through DNA mutation and they try to deduce how all the pieces are connected from the changes in the behaviour of the cell and the other proteins. How successful this is changes a lot depending on the complexity and previous knowledge of the network. As a physicist, I try to apply mathematical tools to this problem, try to get some information through models. I also want explore certain questions about how this networks generally work that biologists usually don't ask themeselves (due to differences in perspective)


In particular, I'd like to concentrate on developmental biology. What is it? Well, I like to think of it as a big question: How can an egg cell become a baby? How does an individual cell that it has to transform into the futur nail of the future finger?
But this is another story for another day.