Minimal genome

Gene functions in Syn 3.0, a minimal-genome variant of Mycoplasma genitalium

The minimal genome is a concept which can be defined as the set of genes sufficient for life to exist and propagate under nutrient-rich and stress-free conditions. Alternatively, it may be defined as the gene set supporting life on an axenic cell culture in rich media, and it is thought what makes up the minimal genome will depend on the environmental conditions that the organism inhabits.[1]

This minimal genome concept assumes that genomes can be reduced to a bare minimum, given that they contain many non-essential genes of limited or situational importance to the organism. Therefore, if a collection of all the essential genes were put together, a minimum genome could be created artificially in a stable environment. By adding more genes, the creation of an organism of desired characteristics is possible. The concept of minimal genome arose from the observations that many genes do not appear to be necessary for survival.[2][3]

In order to create a new organism a scientist must determine the minimal set of genes required for metabolism and replication. This can be achieved by experimental and computational analysis of the biochemical pathways needed to carry out basic metabolism and reproduction.[4] A good model for a minimal genome is Mycoplasma genitalium due to its very small genome size. Most genes that are used by this organism are usually considered essential for survival; based on this concept a minimal set of 256 genes has been proposed.[5]

Scientifically, minimal genome projects allow the identification of the most essential genes, and the reduction of genetic complexity, making engineered strains more predictable.[6] Industrially and agriculturally, they could be used to engineer plants to resist herbicides or harsh environments; bacteria to synthetically produce chemicals; or microbes to produce beneficial bio-products.[6] Environmentally, they could be a source of clean energy or renewable chemicals, or help in carbon sequestration from the atmosphere.[6]

  1. ^ McCutcheon, John P.; Moran, Nancy A. (2012). "Extreme genome reduction in symbiotic bacteria". Nature Reviews Microbiology. 10 (1): 13–26. doi:10.1038/nrmicro2670. ISSN 1740-1534. PMID 22064560. S2CID 7175976.
  2. ^ Maniloff, Jack (1996). "The Minimal Cell Genome: 'On Being the Right Size'". Proceedings of the National Academy of Sciences of the United States of America. 93 (19): 10004–6. Bibcode:1996PNAS...9310004M. doi:10.1073/pnas.93.19.10004. JSTOR 40326. PMC 38325. PMID 8816738.
  3. ^ Mushegian, Arcady (1999). "The minimal genome concept". Current Opinion in Genetics & Development. 9 (6): 709–14. doi:10.1016/S0959-437X(99)00023-4. PMID 10607608.
  4. ^ Ogata, H.; Goto, S.; Sato, K.; Fujibuchi, W.; Bono, H.; Kanehisa, M. (1999). "KEGG: Kyoto Encyclopedia of Genes and Genomes". Nucleic Acids Research. 27 (1): 29–34. doi:10.1093/nar/27.1.29. PMC 148090. PMID 9847135.
  5. ^ Hutchison Iii, C. A.; Peterson, SN; Gill, SR; Cline, RT; White, O; Fraser, CM; Smith, HO; Venter, JC (1999). "Global Transposon Mutagenesis and a Minimal Mycoplasma Genome". Science. 286 (5447): 2165–9. doi:10.1126/science.286.5447.2165. PMID 10591650.
  6. ^ a b c Cho, M. K.; Magnus, D; Caplan, AL; McGee, D (1999). "Ethical Considerations in Synthesizing a Minimal Genome". Science. 286 (5447): 2087, 2089–90. doi:10.1126/science.286.5447.2087. PMID 10617419. S2CID 83279090.