Having repelled Magneto's attempts to snub out the plain-Jane homo sapiens in X-Men 1 and 2, the third installment sees the world's mutants offered a chance for normalcy when a well-known biotechnology company comes up with a 'cure' for mutancy.
Will the gang decide to give up their X-factor genes in favour of integration into the human species, or keep their powers and remain alienated? Of course, I don't want to give away all the secrets of the movie so if you haven't seen it yet, it's safe to read on... I'd much rather dig a little deeper into this business of the X-gene.
No matter how big a comic fan you are, X-Men probably isn't how you've first heard of the term DNA. Maybe your biology teacher has already tossed the word around in class or perhaps you've watched an episode of CSI and seen an investigator use DNA evidence to prove that someone was at the scene of the crime.
DNA (which stands for deoxyribonucleic acid) is how our cells store all of the genetic information required to make a whole person. Chemically, DNA is made up of individual units called nucleotides that are joined together in very long strands. Each nucleotide consists of a sugar molecule, a phosphate group and one of four nitrogen-containing molecules called bases (guanine, cytosine, adenine or thymine).
The four nucleotides are repeated in various sequences to create units called genes,and these genes are read by the cell as an instruction manual for making proteins (the molecules that really get things done around the cell).
Did You Know? DNA is the blueprint of life - it contains all the information needed to make a human being
Since every single cell has its own copy of DNA, every time a cell divides,it has to duplicate its DNA so that each daughter cell receives a copy (a process called DNA replication). Sometimes, mistakes are made, and if they're not repaired, we end up with DNA mutations. In addition to these 'spontaneous' mutations that happen as the result of regular cell division, DNA mutations can also result from damage caused by environmental factors like X-rays, sunlight and cigarette smoke.
Did You Know? Mutations happen as the result of errors made during DNA replication or from natural insults like sunlight, x-rays and pollution
Now you may be thinking, 'Mutations sound harmful! If I've got a mutation in my DNA, am I going to get sick? Or, could I become a mutant and get super powers like the X-men?". Well, as with most things, it's not quite that simple.
First, there are different kinds of DNA mutations. Some are perfectly harmless and create different, but equally functional versions of the same gene, known as alleles.These are actually necessary to maintain genetic diversity within a population - a good thing since that means our gene pool is healthy and keeps each of us unique.
Other changes to DNA aren't so good and can cause serious diseases like cancer. This usually happens when changes in the DNA sequence cause cells to make malfunctioning proteins. Some DNA mutations make proteins that are too short or too long. Others end up totally the wrong shape or simply unable to carry out the chemical reaction they were designed to do.
Did You Know? Mutations in DNA can be harmless and go unnoticed or can cause cause serious diseases
Second,scientists have shown that only a very small part of our DNA sequence actually codes for proteins. In fact, a large chunk of our DNA contains very long stretches of DNA that don't code for anything and whose purpose scientists can't yet explain. It also turns out that countless DNA mutations occur in these regions, apparently without any effect! Mutations in these regions actually serve quite a useful purpose for forensic scientists as they use these sequences for DNA 'fingerprinting' analysis.
So, just how did these X-Men get their special powers? Comic book lore has it that the X-gene has always existed in all of us, usually lying quietly in the background, and only showing itself in a fraction of the population!
Amazingly,the combination of this mystery DNA we've all got, plus the reality of unique spontaneous mutations, has got some die-hard X-fans believing that random, unexplained mutations, such as growing wings or shooting lasers out of your eyes, is completely plausible!
Unfortunately for them, the foundation of what we do know about DNA right now makes it pretty much impossible for any of us to ever leap tall buildings in a single bound...yet.
The X-Men movies: http://www.X-Men-movies.com/
DNA and Applications http://www.koshlandsciencemuseum.org/exhibitdna/index.jsp
"Principles of Genetics, 4th edition" 1993 Wm. C Brown Communications Inc., Dubuque IA. Robert H. Tamarin
"Genetics 101: DNA mutations" http://www.genetichealth.com/G101_Changes_in_DNA.shtml
Shawna got her bachelors in Biochemistry from the University of Waterloo. She has continued to chase down undiscovered scientific facts while pursuing a PhD and post doc in the Department of Medical Genetics and Microbiology at the University of Toronto. Now Shawna chases biotechnology students at Centennial College (where she teaches part time) and her 1-year old daughter. And when she finds the time,she still chases the guys ahead of her in ½ marathons and triathlons.