Studying How Mice Adapt To Changes

Apr 9, 2016 By Arun Sethuraman
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In the previous article, I showed you how we can study fundamental biological questions using bioinformatics.

But that is just one part of the story. What would happen if these red and white mice were moved to an environment that was bad for the red mice? Or what would happen if you separated the mice into different environments?

These are the questions that I am interested in and continue to address through my research. But first things first, we need to understand DNA. To read more about DNA and genome, read our previous article here. 

What Happens When A Population Splits?

When a population suddenly splits up – say you decide to capture some red and white mice from our example and release them into a warm and tropical country, far away. A lot of very cool things happen. For starters, the mice are in the middle of a changing, or a new environment – new warm temperatures, a new environment (white, sandy shores), new food (no more cheese, only fruit), new competition for food (fruit flies love bananas too!), new predators (crows like mice!).

These are all potential sources of what we call “natural selection” – mice that survive these sudden changes will live to pass on their genetic material (DNA) to their babies. Also, since there are fewer mice compared to the original population,  a new gene that lets the white mice moms make more babies than before will be quickly passed on to all babies (due to genetic drift within a few generations – remember our example from Week 2?).

The result – unique and an almost new species (or sub-species) of mice that are so different from the founding red and white mouse population.

So What Do We Really Do?

We conduct experiments in the field – we sample species in their natural habitat, and collect DNA samples (obtained from blood, skin, hair, feces), bring them back to the laboratory, extract genetic material from these samples, then “sequence” DNA using modern techniques. Sequencing refers to the process of identifying the smallest building blocks of the DNA, and their exact arrangement. This gives us a giant “instruction booklet.”

This booklet (“genome”) contains crucial information about how the species lives, grows, reproduces, and dies. For example, if we sequence DNA from the mice, we would expect to find information about the “genes” that are responsible for their coat color – why are some mice red, while others white? We then write computer programs to study similarities and differences in these DNA sequences. 

So, where do we go from here? There are yet many unanswered questions – for example, can the red and white mice mate with each other to produce babies with lighter coats, and thus escape being spotted by crows? Or can a new “white” genetic mutation in the red mice increase their chances of survival?

We are still working on developing new methods to understand these. Importantly, bioinformaticians like me work hand-in-glove with biologists and computer scientists to come up with these solutions.

Can you think of an unanswered question in your mind that can be solved using a computer program? Leave your comments, and let’s come up with solutions!

Comments

azettervall's picture
azettervall August 11, 2016 - 2:06pm

ok