We can create cars, so why can't we make cells?

Let's assume that you don't know anything about cars, so you want to know how they work. By chance you have a friend who is a car repairman so you ask him to explain the car to you.

How do they start? How does burning gasoline cause the engine to move? How is the force generated by the motor turning to the rudder? Imagine that to answer your answer, the friend transports you to an auto parts store and begins to explain what each one is. And at the end of this little lesson, the friend shows you each spare part in the car and explains their functions. So did you know how a car works?

Ah, of course not. Even when you can tell each department what to do, you can still know little about how the parts work together to make the car run. Try a more dramatic case: you're teaching a whole class of ambitious auto engineers, and you want to teach them how to build cars. Do you teach them just by preaching all the car parts one by one? Or you can collect them all at the end of the lesson and show them some of the charted parts together: chassis, electrical system, powertrain.

But even with these charts, these future engineers still can't come to work for Mercedes and create the most advanced next engine. Lists and charts of parts are not enough; As an engineer tells you, you need to have quantitative, you need to understand math and physics, and you need to be able to create model engines on computers, models that you can then Check with your computer system without trying to build any new ideas for an engine.

In many ways, molecular biologists are like a class of auto engineers. We have very long lists and explain the cell components and we have a lot of diagrams of how these components work together, but we don't understand a cell in the same way as one. Audi car masters understand a car engine.

Biologists try to change that and their efforts are part of a new field that most people have never heard of, known as systems biology. Although system biology has yet to prove it powerful, Harvard University Medical School is so confident in the potential of this field that the school has established a System of Biology, a complete faculty. The new full-fledged first for the past 20 years, and Nature magazine publishers have produced system biology magazines.

So, how does this field work?

Cold Spring Harbor Laboratory is home to molecular biology. Many great molecular biologists of the 20th century went to this lab to work or attend meetings, and the walls of the lab building were filled with molecular biology pictures. history, including a guitar signed by dozens of leading genome biologists and a huge portrait of James Watson.

On a recent cold spring weekend in New York, about 300 systematic scientists interested in biology gathered at Cold Spring Harbor to discuss. To get an idea of ​​the problems that this scientific community is facing, take a look at one of the most well known cells: yeast. Men have about 6000 genes, and we know about what 75% of those genes do - you can choose your favorite yeast gene, go to the database and read what that gene does in the cell. yeast.

Dr. Robert Waterson (Photo: washington)

In a few years, we will know what 99.9% of yeast genes are. But will we really understand even a simple creature like yeast? Yeast cells produce a process very similar to the way that human cells divide and as a result we know a lot of basic biology that is involved in human diseases like cancer by enzyme research. An enzyme cell division model like the computer model of an engine can shed light on how important it is for damaged control systems in diseases like cancer. But right now we all have long lists of components and some basic diagrams - not enough to create any cell.

This problem is raised again in the genome-linked studies, studies that have published lists of genes that may be related to diseases such as diabetes and heart disease. Do we understand these diseases better when we have such lists? Actually, no, because we don't know how those ingredients fit together into health or disease.

So what are system biologists doing to this problem? The truth is, they also write down long lists of genes related to a certain biological process, but many research groups are investigating how these ingredient lists change over time: Which gene is turned on or off when a stem cell breaks down into a neuron? Which gene is active in any cell when an embryo develops from a single cell? Which stem cells increase muscle cells and neurons? Here are some outstanding topics being studied in system biology.

Discovering which stem cells increase adult cells is a research focus of Dr. Robert Waterston at Washington University:

Dr. Waterston has developed an incredible imaging technique capable of tracking individual cells in a deep embryo, following an original stem cell during all of its division. when different parts of the worm develop.

Dr. Jeanne Loring, at Scripps Institute, is studying changes that occur in single embryonic stem cells as they differentiate into other cell types. She is studying the mechanism of DNA methylation (DNA methylation) in stem cells as they change. Knowing how this mechanism changes over time is a key part of how all of our different cell types have the same DNA but work differently.

And at Harvard, Dr. Sunney Xie is using sophisticated microscopy to study how the components of biological systems work naturally within living cells. He could see individual protein molecules inside individual cells and measure how fast a regulatory protein slides along a DNA strand, and a cell can produce a protein when reacting to a signal. How fast the environment is and how many protein molecules are needed to start a positive feedback loop.

System biology is still an 'immature' field, striving to clarify the most pressing scientific questions and to identify the most promising research routes. At the Cold Spring Harbor meeting, it is clear that while some people are doing extremely interesting research, we still have a long time to create a computer cell model, or even one. Small cell subsystems with which we can simulate changes caused by drugs or mutations.

A Mercedes car engineer with a new idea for engine improvement can test it on the previous model but a pharmaceutical company with a new potential drug can't do the same, it can't predict anything. about how the cell will react to it. We may be far from that goal, but system biology is an area of ​​great interest.