Synthetic biology is an emerging discipline that is building on biotechnology’s current successes. However, unlike traditional biotechnology that has so far generated engineered organisms containing a single or a few transgenes, synthetic biology aims at producing organisms containing large numbers of modified genes or transgenes or even of novel synthetic genes. These genes will have to be expressed coordinately and at the right level to provide the desired phenotype. To reach this goal, synthetic biology will need tools that provide the ability to engineer large number of genes in complex constructs and in multiple variant combinations. One essential element of synthetic biology consists of standardization of parts. This allows the use of a standard DNA assembly procedure, which in turn increases the throughput of plasmid construction. Standard parts can also be reused easily in different constructs using a similar assembly procedure, and can also be easily exchanged between different users.
We have been developing a standardized cloning system called MoClo that allows assembly of any multigene construct of choice from libraries of standard biological parts (Weber et al., 2011, A modular cloning system for standardized assembly of multigene constructs. PLoS One 6: e16765). Moclo standard parts consist of basic genetic elements such as promoters, coding sequences and terminators cloned between two BsaI sites as level 0 modules. Level 1 constructs containing functional transcription units are assembled from sets of standard parts using a first Golden Gate cloning reaction. Level 1 constructs can then be assembled in multigene constructs using one or several additional assembly reactions (Fig. 1).
One goal of our lab is to further develop the technology required to assemble complex constructs and to develop technologies for transformation of such constructs at specific locations in the host species genome of choice. Part of this work also includes the development of libraries of standard biological parts for a number of species of interest, as these are the basic building blocks that are required for all synthetic biology projects. A second goal of the lab is to apply this technology for metabolic engineering of plants or microorganisms.