Contents 1 Ethics 1.1 Public Health 1.1.1 PEALS 1.1.2 Agriculture 1.1.3 Scientists 1.1.4 The Public 1.2 Environmental Safety- Plants 1.3 Environmental Safety- Genome Shuffling 1.4 Environmental Safety- Resistance Markers 1.5 Future 1.6 References

Ethics

Public Health

Synthetic biology is a rapidly emerging field, but it is still in a very early stage of its development. It is vital to encourage debate with relevant stock holders and the general public in order to investigate the ethics that arise from this research. Therefore, in this section we aim to discuss the ethics relevant to our project.

PEALS

On the 1st of August, our team had a discussion with the executive director, Professor Janice McLaughlin from Policy, Ethics and Life Sciences (PEALS) Centre regarding ethics and biosafety. She helped us identify the relevant sock holders to our project and brought our attention to some topics that we may wish to explore further.

Agriculture

One of our project sub themes involves inserting L-forms in to plants, visualising them and considering their benefits. These plants include crop plants, therefore this topic may raise concerns regarding agriculture and farming. We are interested in the opinions, ideas or concerns that an agriculture representative may have regarding this topic.

Scientists

The Public

Environmental Safety- Plants

Our team is suggesting the use of L-forms instead of normal bacteria or genetically modifying plants to provide benefits to plants. This is because we believe that using L-forms will be safer and have fewer ethical issues, as discussed here. However there are still safety and ethical issues to consider.

Our BioBrick for turning B. subtilis cell walls on and off could mutate, the cells regaining their walls regardless of the presence of xylose. However, it would be reasonably simple to produce a similar mutant, in which part of or the entire murE operon has been removed. As our BioBrick controls the expression of this operon the effect should be the same. It would not be feasible for random mutations to mask this, as functions of multiple genes essential to peptidoglycan synthesis would have to be replaced.

The murE operon contains the gene Spovd. Although involved in peptidoglycan synthesis, the product is involved in sporulation. Could our BioBrick have a further effect, inhibiting the ability of B. subtilis to sporulate? We are currently considering methods of exploring this. Sporulated bacteria are very difficult to destroy, able to survive for long periods of time in near-extreme conditions. Our L-forms burst in the harsh conditions which induce sporulation.

Establishing whether our bacteria can survive in the wild is only the first step when considering the safety of releasing plants containing our L-forms into the environment. Could DNA released by burst L-forms be incorporated by other bacteria? If so, what effects could this have? What would happen to animals that ingest plants containing our L-forms?

Although there are naturally occurring L-forms that appear to survive (and indeed subsist) in the human body, our L-forms do not survive in the pH and osmotic conditions found in the stomach and digestive tract. It should also be stressed that our L-forms should be harmless, as the B. subtilis we have modified is. However there are ways in which cell wall free bacteria could be harmful, if they were able to survive harsh osmotic conditions. It has been speculated that L-forms are difficult for the immune system to detect, having lost many of the antigens found on the cell wall. Furthermore, many popular antibiotics, including penicillin, work by targeting the cell wall. L-forms are therefore resistant to these, which would make them quite difficult to kill if not for their inherent fragility.

Environmental Safety- Genome Shuffling

The fusion of two cells of the same species causes genetic recombination to occur. This technique has started to be explored in bacteria as a method of directed evolution, as discussed here.

Genome fusion is interesting as it causes recombination over the whole genome, rather than a specific gene, and the recombination occurs randomly across random segments of the genome. This means that we don’t necessarily know, or need to know, the genes responsible for a chosen process to ‘improve’ said process. Furthermore, we won’t know why the improvements have occurred without further, optional, study. Is this important? Could we unknowingly be creating potentially harmful bacteria?

Yes. One could assay already harmful bacteria for increased pathogenesis, for ability to survive against immune system components. Research has even been done in a similar area where viruses were evolved to reproduce as quickly as possible (though the viruses quickly lost the ability to infect cells). Thankfully there are incredibly stringent rules for obtaining and working with pathogenic bacteria.

But could we accidently produce dangerous bacteria? Admittedly many of the traits desirable in ‘useful’ bacteria- sturdiness, rapid replication- are also those which cause increased pathogenesis. It should be noted that we are proposing the fusion of bacteria of the same species. Whilst the base composition of our ‘progeny’ may be unique, the genes will be same. There will always risks, a protein gaining a novel product, a gene switched off, but these are not risks that are unique to our project- they apply to any kind of breeding. However, as the many de novo negative mutations that arise even from human reproduction, we do need to be careful.

There are risks with not understanding how or why our experiments have modified the bacteria on a genetic level. If adverse effects are expressed de novo by our bacteria, it may be difficult to understand what has caused them- as it could be due to modifications in any number of the organism’s genes- our process can modify all of them!

Environmental Safety- Resistance Markers

Our L-forms also currently contain antibiotic resistance markers. These allow us to grow the L-forms up without risk of contamination. However, if released into the wild these genes could pass into other, pathogenic bacteria, reducing the effectiveness of various antibiotics in medicine. Antibiotic resistance is already a major problem facing healthcare! Therefore not only is releasing bacteria containing antibiotic resistance conferring genes dangerous, it is also illegal.

Future

References