Entire genetic code printed in books | An introduction to genetics

Entire genetic code printed in books | An introduction to genetics


Hello humans.
My name is Nick Dent and this… is your Genome Project. Now when this was completed
it made a lot of people very excited. The UK science minister Lord Sainsbury said, ‘We now have the possibility to achieve all
we ever hoped for from medicine’. President Bill Clinton said, ‘We are learning the language
in which God created life’. And my mother said,
‘What a lot of big white books!’ So what is it that got my mother and
William Jefferson Clinton so excited? Well, the Human Genome Project is a
collaboration between several countries: it was France, Germany, China, Japan,
USA and United Kingdom working together to map all of the genes –
collectively known as the genome – of the often less than humble homo sapiens. So to put it marginally simpler, this will tell you where to find
all of the genes in human DNA. These are the instruction booklets that
your body follows when building a human being. So how does your body use these
to make a human being? Well, these letters represent nucelobases in DNA. Now here I have a model of DNA. This structure was discovered in 1953
by James Watson and Francis Crick, with honourable mentions to
Maurice Wilkins and Rosalind Franklin. So here we have the phosphate backbone, but in the middle we have the nucleobases. There are four different nucleobases: there is Adenine which is
represented in these books by an ‘A’; Thymine, ‘T’; Cytosine, ‘C’,
and Guanine, ‘G’. So they bond here in the middle,
forming the double-helix shape. Now Adenine will only bond to Thymine, and Guanine will only bond to Cytosine. So if you know the structure of one strand, you can actually use this to deduce
the structure of the other one. So how does a language using only
four letters ordered by random chance create the wonderful poetry that is my body? Well, you’ve heard the story that if you give
a monkey infinite time and a typewriter he’d write the complete works of Shakespeare. Well, if you only give him four letters
he couldn’t even type, ‘Shakespeare’. So the truth is this language
doesn’t just use four letters; these four letters are grouped
into threes called ‘codons’. Theoretically, you could combine
these letters in 64 different ways. And these codons can code for
20 different amino acids. Now if you think we have 26 different letters
in the English alphabet and these can make all of the wonderful words
and stories that you’ve ever heard. So 20 is starting to sound like a more
viable number to create a human being. So these amino acids combine to form proteins. And these proteins can join together
in bundles to form tissues. This is why mutations can be so dangerous, because if you change one codon
it changes the amino acid, which changes the protein,
which changes how it combines. And this can kill you – or give you superpowers! So as you can see by these books,
you have a lot of DNA. There are three billion letters
or bases in these books. And bear in mind, you have this information
in nearly every single one of your cells. And they produce a staggering amount of DNA. If you stretched out the DNA from one cell
it would reach two metres high, that’s roughly the height of these books. And bear in mind, you have
nearly 40 trillion cells in your body. So combined they create enough DNA
to stretch nearly 50 times around the world. However, only 2% of our genome are actually genes. This amounts to just under 21,000 genes. This is less than a water flea;
this is half as many as a potato. Now most people you meet will be
slightly more complicated than a potato, so scientists soon had to realise
that bigger is not necessarily better. Changes in this 2% can affect many things: it can affect your hair colour,
it can affect your height, and sadly it can even affect
whether you live through childhood. So there’s a lot of amazing information
hidden away in these books. So you can imagine the excitement when
in 2006 they finally finished this project. They opened up the books;
they looked at them and thought, ‘Oh…’ Because essentially they had just created
a dictionary for a language nobody could speak. So for the last ten years they’ve
been trying to decode these books. So how do you find out what a gene does? Well there are several different ways. One way is to look at an animal
that might have the same gene as us. So when you think of experimenting on animals
most people imagine lab mice, however a vast amount of work is done
on things like drosophila or fruit flies. So, for instance, if you find a gene in them
and you remove it, and when they are born they don’t have any eyes you could deduce that perhaps
this gene was to do with eye production. However, it is rarely that simple. A second way is to insert a gene into bacteria. For instance, if you found a gene that was being
expressed loads and loads in the pancreas and you put it into bacteria
and they started producing insulin, you could deduce that perhaps
this was the gene for insulin. Finally, you can compare groups of humans. So I actually have a genetic condition,
one called psoriasis. It’s not the worst one in the world
and I don’t have it particularly badly. But if we got a group of people with psoriasis and compared their DNA to a group without psoriasis, any consistent differences could perhaps
be a gene, which controlled skin production. Now this can be done for any genetic disease,
or indeed any genetic trait, However, many traits are actually governed
by many genes working together, such as height, so it is not always that easy
to pinpoint them. So what if we actually find a gene
which causes a genetic disease? Well, many people think we should do nothing because messing with this code
is tantamount to playing God. However, many people see this as the potential
to remove inherited diseases from the human race and improve the life of millions of people. Scientists have been working on ways
to alter the genome using ‘molecular scissors’ and over time these results have become
more accurate and more reliable. This gives us the potential to cure diseases
as wide-ranging as cystic fibrosis to haemophilia. Some people even believe that we could alter our
immune system to combat diseases such as HIV. So the future is coming and the information in these books
has the potential to change the world, and I for one am quite excited.

4 thoughts on “Entire genetic code printed in books | An introduction to genetics

  1. Hi, you mention the old Evolutionary argument that an infinite number of monkeys with an infinite number of typewriters would eventually produce all the great literary works. This concept was disproved by a statistician shortly after it was proposed. As each letter is typed, correctly choosing the next letter by random chance becomes, in a short time, statistically impossible.

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