In 1995, a quite extraordinary experiment was carried out at the University of Basel. It was described at the time as “Frankenstein science at its best”. And I have to say, I did feel a little squeamish after reading about it.
The study was conducted by three scientists: Walter Gehring, Patrick Callaerts and Georg Halder. These scientists genetically doctored larvae, inserting a particular gene known as the ‘eyeless’ gene into areas destined to become wings, legs and antennae. But they were staggered by the result. When the flies matured, they noticed that the eyes began to grow on their wings and even on the end of their antennae.
In fact these three scientists had found the master control gene for the formation of the eye, one of the most complex structures in nature. Their work overturned conventional theories about eye development that assumed that, in view of the vast differences between the visual systems of many different organisms, the eye had been invented many different times.
But although a human eye with its single lens looks nothing like the fly’s compound eye, this study found that the primordial eye may in fact have evolved only once, taking on manifold shapes and designs depending on the needs of the organism. Even the squid appears to have its own version of the eyeless gene.
Why am I telling you this? Well the fact is that these types of experiments are part of the story of biotechnology. Sure, some of them may be gruesome. But I want to show you today how the discoveries that scientists are making today could deliver truly remarkable changes in your life over the next few years – in everything from food production to the treatment of cancer. It’s a story that you really can’t ignore, no matter how squeamish you might be.
The power of a single chromosome
Flies get a rough deal in biotechnology. Because they grow so quickly their life cycle can rapidly be assessed. In 1910, Thomas Hunt Morgan set up the Fly Room at Columbia University. There he mated white-eyed male mutant flies with red-eyed flies, and found that the offspring all had red eyes, suggesting the red colour was dominant.
But when the second generation of flies was mated white-eyed individuals reappeared. These were all on male flies, suggesting that eye colour was linked to sex. When the flies’ chromosomes were examined under a microscope Morgan was able to infer that the gene for eye colour was located on a specialised sex chromosome that determined both sex and eye colour. This was the first time that a trait had been correlated with the presence or absence of a chromosome. It was a hugely important discovery.
Edward Lewis, Eric Wieschaus and Christiane Nüsslein-Volhard, who won the Nobel Prize in Physiology or Medicine in 1995, also made use of flies. These flies were exposed to chemical mutagens which caused a host of random mutations in their DNA.
The result was a collection of twisted and deformed flies, which were then studied in order to identify the specific gene responsible for the resultant abnormality. Reasoning that if the technique had worked so well with flies it could equally be applied to fish, Nüsslein-Volhard set up a laboratory containing 6,000 fish tanks, filled them with a type of zebrafish and filled the tanks with mutagenic chemicals. By doing so she created 1.2 million fish with development errors at every stage, including those that twitched uncontrollably and others that swam in continuous circles.
The first GM animal could help feed the world
Ever since dwarfs and Siamese twins have been paraded as circus entertainment we have been fascinated by so-called ‘freaks of nature’. But only now are we starting to understand the genetic causes. The first sequencing of the human genome took ten years, cost $3bn and was completed in 2003. Since then there has been an extraordinary advance in our ability to sequence the genome of living things, from the human body down to the humblest bacteria.
All over the world biotechnologists are mapping genomes, the recipe for life. Armed with this knowledge, it is possible to alter the recipe through genetic manipulation, and today genetically modified crops are grown in over 40 countries. Take this example…
Just before Christmas I spotted one of the most significant announcements of 2012, from Aqua Bounty Technology Inc (ABTX), a US company that has its shares traded on AIM.
The US Food and Drug Administration has indicated its inclination to approve Aqua Bounty’s AquAdvantage Salmon, having found that they are safe to eat and do not pose a threat to the environment. These salmon are created by inserting the growth hormone gene from the Chinook salmon into Atlantic salmon eggs, which allows them to reach market size in half the time of conventional Atlantic salmon.
Furthermore, and to heed off any criticism that they could breed with and destroy natural salmon, these genetically engineered fish will be sterile, exclusively female and grown in landlocked pools. This salmon could be the first GM animal to hit the dinner table. That is stunning news for diners, for farmers, for all those concerned with feeding the world’s population – and for biotechnology.