Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 11 (1), 9

Just How Lamarckian Is CRISPR-Cas Immunity: The Continuum of Evolvability Mechanisms

Affiliations

Just How Lamarckian Is CRISPR-Cas Immunity: The Continuum of Evolvability Mechanisms

Eugene V Koonin et al. Biol Direct.

Abstract

The CRISPR-Cas system of prokaryotic adaptive immunity displays features of a mechanism for directional, Lamarckian evolution. Indeed, this system modifies a specific locus in a bacterial or archaeal genome by inserting a piece of foreign DNA into a CRISPR array which results in acquired, heritable resistance to the cognate selfish element. A key element of the Lamarckian scheme is the specificity and directionality of the mutational process whereby an environmental cue causes only mutations that provide specific adaptations to the original challenge. In the case of adaptive immunity, the specificity of mutations is equivalent to self-nonself discrimination. Recent studies on the CRISPR mechanism have shown that the levels of discrimination can substantially differ such that in some CRISPR-Cas variants incorporation of DNA is random whereas discrimination occurs by selection of cells that carry cognate inserts. In other systems, a higher level of specificity appears to be achieved via specialized mechanisms. These findings emphasize the continuity between random and directed mutations and the critical importance of evolved mechanisms that govern the mutational process.

Figures

Fig. 1
Fig. 1
The Lamarckian scenario for the CRISPR immune response: efficient self-nonself discrimination
Fig. 2
Fig. 2
The Darwinian scenario for the CRISPR immune response: random spacer acquisition with subsequent selection
Fig. 3
Fig. 3
Evolution of mechanisms for repair and evolvability

Similar articles

See all similar articles

Cited by 7 articles

See all "Cited by" articles

References

    1. Gissis SB, Jablonka E. Transformations of Lamarckism: From Subtle Fluids to Molecular Biology. Cambrdige: The MIT Press; 2011.
    1. Lamarck J-B. Philosophie zoologique, ou exposition des considérations relatives à l'histoire naturelle des animaux. Paris: Dentu; 1809.
    1. Burkhardt RW., Jr Lamarck, evolution, and the inheritance of acquired characters. Genetics. 2013;194(4):793–805. doi: 10.1534/genetics.113.151852. - DOI - PMC - PubMed
    1. Darwin C. On the Origin of Species. London: Murray; 1859.
    1. Darwin C. Origin of Species. 6. New York: The Modern Library; 1872.

MeSH terms

LinkOut - more resources

Feedback