1 Department of Systems Biology, Technical University of Denmark2 Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark3 Max Planck Institute4 Yale University5 International Dialogue and Conflict Management6 Comparative Microbial Genomics, Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark7 University of Hong Kong
A central undertaking in synthetic biology (SB) is the quest for the ‘minimal genome’. However, ‘minimal sets’ of essential genes are strongly context-dependent and, in all prokaryotic genomes sequenced to date, not a single protein-coding gene is entirely conserved. Furthermore, a lack of consensus in the field as to what attributes make a gene truly essential adds another aspect of variation. Thus, a universal minimal genome remains elusive. Here, as an alternative to defining a minimal genome, we propose that the concept of gene persistence can be used to classify genes needed for robust long-term survival. Persistent genes, although not ubiquitous, are conserved in a majority of genomes, tend to be expressed at high levels, and are frequently located on the leading DNA strand. These criteria impose constraints on genome organization, and these are important considerations for engineering cells and for creating cellular life-like forms in SB.
Trends in Genetics, 2013, Vol 29, Issue 5, p. 273-279