By Aly Muhammad Ladak, Staff Writer
Life on Earth is astoundingly complex and diverse – and yet, the same core biological rules govern nearly all living things. We have gained a better understanding of these principles over the past few decades and, though there are still far more questions than answers, scientists are beginning to develop ways to engineer new forms of life. This field, where scientists modify, or potentially create, organisms to perform new functions, is known as Synthetic Biology. It is one of the most rapidly growing fields in biology, particularly in terms of startups. Just last month, Gingko Bioworks (a key player in this field) went public with a valuation of over 17 billion dollars. However, given the field’s vast scope, young age, and interdisciplinary nature it can be hard to see what synthetic biology actually means and where it is headed.
Here are five key areas that synthetic biology – SynBio for short – has the potential to revolutionize.
Most companies in the SynBio space are currently focused on harnessing the power of biological systems to manufacture chemicals and products. According to Joshua Dunn, head of design at Gingko Bioworks, “what we’re trying to do in synthetic biology is… engineer nature to do something that we want it to. So, synthesize a vitamin, detect something in the environment, or make a food product that you don’t normally make.” Bacteria or other microorganisms have long been genetically engineered to grow drugs in particular – for instance, this is how most insulin is made. However, scientists are now making strides to produce molecules we didn’t think possible. In fact, the most prominent success of synthetic biology this far has been in synthesizing a particular drug. Artemisinin is one of the best-known drugs that can treat current forms of malaria – the 2015 Nobel prize in medicine was awarded for its discovery. However, it can only be isolated from sweet wormwood, a small plant native to parts of Asia. This makes it expensive, and costly to biodiversity, to harvest this drug. Unlike other drugs, for instance, insulin, the process to synthesize artemisinin in tissues is very complex and involves a lot of specific conditions and chemicals. Nonetheless, the tools of SynBio successfully recreated the synthesis pathway in yeast, which is now the primary method of creating the drug. This also allows us to change certain parts of this pathway to create slightly different drugs that might work better.
Given that over a quarter of all drugs in use today have their origins in plants, and even more in other organisms, being able to recreate, engineer, and improve complex biosynthetic pathways could vastly improve our ability to treat diseases. There is also the possibility of synthesizing chemicals beyond drugs – like food products, fragrances, plastics, and so on. This means that the only limit is our understanding of biological pathways, which will no doubt improve over the coming years.
2. Biological Computing and Circuitry
One paradigm often used to understand biology is that of computing. Your genes are seen as the ‘code’ for life’s processes and are processed by the ‘hardware’ of the cell. However, there is some hope that we can use biological molecules, or even cells, as actual computing devices.
In some sense, this has been occurring for decades. In the 1990s, several scientists and mathematicians developed DNA computers – they used the physical properties of DNA molecules to solve certain mathematical problems in a more efficient way than traditional computing. However, the impacts of biological computing may extend far beyond niche mathematical problems. There are a number of companies today trying to store data on DNA molecules – using the sequence of A’s, T’s, C’s and G’s of DNA building blocks instead of the 1’s and 0’s of a computer chip. If fully realized, this could result in storage that is far more efficient, stable and cheaper than traditional methods. Finally, although it is still at a very early stage, some scientists are trying to generate cells that function as computing machines. In 2013, scientists at Stanford succeeded in developing a biological counterpart to the transistor, a key component of computing. Whether this will lead anywhere is still up in the air, but it has the potential to produce powerful, low-energy computing that can do things beyond our imagination
Scientists also hope to create organisms that can detect, and potentially neutralize, substances that are otherwise hard to track. The molecules and pathways used to do this are known as biosensors (coincidentally, a key area of research in UofT’s chemistry department). One key advance in this area has been testing water for lead – while previously water had to be put through several chemical steps for testing, there are now bacteria that change colour in the presence of lead in water. This means that testing can occur with relative ease and that remote water sources can be quickly assessed for contamination and viability as sources of potable water.
The implications of biosensors, however, reach far beyond this. Imagine, for instance, microorganisms engineered to localize oil spills – or others that could find and digest plastics. The key idea here is that rather than collecting and chemically analyzing samples, we can use organisms or biological molecules to seek out target chemicals, and send a signal to let us know where they are.
Synthetic biology also has applications in conservation biology and biodiversity. Scientists have long dreamed of resurrecting extinct species like the Woolly Mammoth or saving those on the brink of being wiped out. However, the question of how has always impeded efforts to achieve these goals. Synthetic biology gives one potential answer for how to do this – if we can biologically engineer parts of a living relative and move closer and closer to their extinct ancestor, we may be able to recreate the extinct ancestor. A recent startup funded by George Church, a Harvard Medical School professor and a key figure in SynBio, hopes to do just that, recreating the woolly mammoth. The project has been met with equal amounts of skepticism and enthusiasm – but if it succeeds, it would represent a massive step forward for humankind’s ability to modify life.
5. Understanding Life
Despite monumental advances in the quantity of biological data we can collect and analyze, much of the information encoded in organisms remains unknown to us. Synthetic biology can help us identify what biological molecules and processes are universal, rather than specific to certain organisms, which can help us understand life on a fundamental level.
A key effort in this area has been the development of the ‘minimal genome’. In simplified terms, think of an organism’s genome (i.e. all of its DNA) as being instructions that tell it how to make the things it needs to survive. Some instructions are crucial for life in all organisms, whereas others are involved in helpful, but ultimately unnecessary, processes. To identify these crucial processes, scientists at the J. Craig Venter Institute replaced the genomes of some bacteria with DNA sequences they had created from scratch. Each time they did this, they would remove more and more instructions from the bacteria’s genomes. If the bacteria were still alive, then great – the removed instructions weren’t required for survival. If they didn’t survive the edit, then that sequence of bacterial DNA would be necessary for its survival. The researchers eventually reached a point where nothing more could be removed – in other words, where everything left was fundamentally required for the processes of life. This core set of instructions, referred to as the ‘minimal genome’, can give us insight into what is required for life, and hence what might be universal across all life on Earth.
The early successes of SynBio – including Artemisinin synthesis in yeast and the minimal genome identification- provide evidence that this field can yield useful results. However, whether it will achieve some of the lofty goals outlined above is still unclear. Prominent companies in the field are struggling to come up with relevant, interesting, and viable results. Gingko BioWorks, for instance, has only produced a few strains of modified yeast to manufacture fragrances. Mammoth de-extinction has been proposed for decades, with little concrete progress being made. But there is still hope that these goals will be achieved – and if they are, they will no doubt change the world.