New possibilities of radically altering a genome
28 March 2014 Scientist in the US have succeeded in re-synthesising a whole chromosome contained in yeast. In the process some changes in the genome were introduced and DNA sequences regarded as non-essential for survival of the yeast cell were removed. The new cells are reported to have similar biological characteristics as the native variants (Annaluru N., et al, 2014). The publication sheds light on the potential of synthetic biology: So far laboratories have not made many advances in creating completely new life forms but, at the same time, the increasing technical potential to radically change the genome of existing life forms has escaped broader public attention. These developments will trigger a whole new set of specific issues and questions on the ethical consequences, social impacts and environmental risks.
The methods used in the re-synthesis involved DNA analysis and synthesis as well as technologies that can be used to achieve far reaching changes in the genome such as gene scissors (site-directed nucleases) and oligonucleotides (short cuts of DNA or RNA) which can be used to do genome editing without transferring DNA. According to the well-known biologist George Church, the new technologies will enable the re-writing of large parts of the genome – including the human genome (Church & Regis, 2012):
„The same technique would work for the Neanderthal, you would start with a stem cell genome from a human adult and gradually reverse-engineer it into the Neanderthal genome or a reasonable close equivalent. … If society becomes comfortable with cloning and sees value in true human diversity, the whole Neanderthal creature itself could be cloned by surrogate mother chimp - or by an extremely adventurous female human.“
Some examples for current applications:
- The US company, Intrexon is relying on the methods used in synthetic genome technologies to radically change the genome of mammals and other organisms. Intrexon is filing patents on all kind of mammals, including chimpanzees manipulated with synthetic DNA stemming from insects.
- The genome of genetically engineered olive flies produced by the UK company, Oxitec is a synthetic combination of DNA from other insects, marine organisms, bacteria and viruses. The intention is that when the genetically engineered flies mate with native flies a lethal gene will be introduced into natural populations that will kill the females while the male descendants will survive and spread their deadly genetic trait.
- SmartStax maize is a joint Monsanto and Dow AgroSciences product. At least one of the toxins it produces, Cry1A.105, is based on a fusion of DNA which does not have a natural template.
Testbiotech believes there several problems that need addressing and require regulation in very near future:
- to protect biodiversity releases must be prohibited if they can end up with uncontrolled spread of the new organisms into the environment;
- to protect the genetic integrity of life forms such as plants and animals it is necessary to develop adequate criteria and new regulatory approaches;
- new approaches to regulate access to specific technologies or genetic information have to be considered if they can be used to produce hazardous organisms.
Christoph Then, email@example.com, Tel 004915154638040