Rates of nucleotide substitution, mutation at a locus, and the "beanbag" gene number in man

• We estimated the number of different human genes by relating the patterns of spontaneous mutation at the population and individual level. A geometric distribution model of mutation was used in which the average rates of nucleotide replacement (P) and mutation at a locus (p), obtained by experiment, were used to determine the estimate of the physical size of the coding genome (n) in man. The probabilistic relation used, P = (1 - p)(n-1)p, integrates two different referential time scales of mutation, that of a nucleotide and year and that of a coding gene and generation. The estimates of n, for different values of P and p, are compatible with the experimentally determined genome sizes. The size of the coding portion of the genome appears to be evolutionarily constrained by an interplay between the rate of nucleotide replacement and the pattern of mutation at the level of the individual locus. The evolution of the size of the coding genome may be more dependent on the number of generations than on time.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Medicinsk genetik (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medical Genetics (hsv//eng)

Keyword

Evolution, Molecular

Genome, Human

Humans

Point Mutation

Publication and Content Type

art (subject category)

ref (subject category)