Journal of Molecular Evolution

, Volume 41, Issue 6, pp 717–720

Variation in synonymous substitution rates among mammalian genes and the correlation between synonymous and nonsynonymous divergences

  • Tomoko Ohta
  • Yasuo Ina

DOI: 10.1007/BF00173150

Cite this article as:
Ohta, T. & Ina, Y. J Mol Evol (1995) 41: 717. doi:10.1007/BF00173150


Using mammalian gene sequences, the variances in the numbers of synonymous and nonsynonymous substitutions among genes were estimated together with the correlation coefficient between the two. The expected correlation coefficient can be obtained under the neutral theory using these estimated values of the variances. The expected coefficient is found to often be one-half to two-thirds of the observed value. Possible causes for the disagreement were discussed, such as correlated selective constraints on the two types of substitutions and excess doublet mutations. The variance of mutation rate and that of selective constraint were also estimated. The results show that the coefficient of variation of the former is 0.2–0.3, whereas that of the latter is 0.7–0.9.

Key words

Neutral theory Correlation between synonymous and nonsynonymous substitutions Variation in mutation rates 

Copyright information

© Springer-Verlag New York Inc 1995

Authors and Affiliations

  • Tomoko Ohta
    • 1
  • Yasuo Ina
    • 1
  1. 1.National Institute of GeneticsMishimaJapan

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