| Guanine-Cytosine content (G+C
content) is a characteristic of the genome of any given organism or any
other piece of DNA or RNA. Usually expressed as a percentage, it is the
proportion of GC-base pairs in the DNA molecule or genome sequence
being investigated. G+G
% = 100 *(G+C/A+C+G+T)
The remaining fraction of any DNA molecule will comprise of the bases A and T, such that calculation of a GC-content indirectly calculates the AT-content as well (e.g. 58% GC-content = 42% AT-content). When new species are described the G+C content is often mentioned (mostly in the past). In prokaryotes, the values for this parameter are between 20 and 78 %. Related strains (e.g., different members from the same specie) show similar G+C content, and microorganisms which different G+C content are not related.
For further information check Wan et al., 2004 |