DNA is an amazingly efficient memory bank for the design and scheduling of biological development. Cell DNA have their own replication systems, but human scientists who want to interfere with the content of the genome have been working to find ways to achieve artificial replication and synthesis of disparate properties, and now they may have achieved a landmark breakthrough.
The new process capitalizes on innovations in genome sequencing (reading DNA). Automated genome sequencing allowed for great leaps forward in the processing of daunting amounts of genetic code, and the eventual sequencing (mapping) of the entire human genome. Decoding the information contained in that map of human genetics was possible only because automation had allowed for a rational amount of time spent to sequence any particular strand.
Now, Harris Wang, a biophysicist from Harvard University, in Cambridge, Massachusetts, and George Church, have co-authored a study, published in this Sunday’s edition of the journal Nature, in which they explain how automated merging of biological DNA and synthetic re-ordered DNA can allow for an automated replication process in which the engineering of whole new genomes piggybacks on the already existing natural process of cell division.
As reported by Wired Science:
Earlier methods of manipulating genomes involved a painstaking biological cut-and-paste process, with target genes removed, tweaked and reinserted, one at a time. Alternatively, bioengineers could use a mutagen that turned genomes to hash.
The technique developed by Wang and Church is called Multiplex Automated Genome Engineering (MAGE), and involves customized single strands of DNA, designed to link up with existing DNA at specific target points. A burst of energy opens the target cell, allowing the synthesized DNA to enter, and in a process akin to how viruses use cell-division to self-replicate, the cell includes the new DNA in its own replication process.
The result is a new “modified” genome, inclusive of the synthesized DNA. The process is far faster than the standard method of “pasting” specific strands of DNA into specific locations in the existing genome. The machines Wang and Church use to process these genome adaptations can reiterate the insertion over and over, creating ever-evolving variants of a given genome, with each replication.
They can also provoke or interact with naturally occurring mutations, which the scientists hope can be tracked and predicted, to make the reworking of DNA both more predictable and more efficient. The technique is optimal at present for conducting research on the nature and evolution of genetic properties, and on testing bold hypotheses for developing functional alterations to existing cells.
For instance, in one MAGE modification, reported in the Nature article, Wang and Church successfully converted E. coli bacteria to work as “factories for lycopene”, producing the special antioxidant that is thought to have properties that allow it to scale back or work against the onset of cancerous tissue.
One potential use for the MAGE process would be the creation of lab “models” of infectious diseases, complete with major genetic alterations or projected mutations, allowing for research on how to confront such evolutions if and when they arise. Such research could allow for the development of anticipatory drug treatments for drug-resistant microbes that have evolved from existing treatments.