Rates of synonymous substitution and base composition of nuclear genes in Drosophila - PubMed (original) (raw)

Rates of synonymous substitution and base composition of nuclear genes in Drosophila

E N Moriyama et al. Genetics. 1992 Apr.

Abstract

We compared the rates of synonymous (silent) substitution among various genes in a number of species of Drosophila. First, we found that even for a particular gene, the rate of synonymous substitution varied considerably with Drosophila lineages. Second, we showed a large variation in synonymous substitution rates among nuclear genes in Drosophila. These rates of synonymous substitution were correlated negatively with C content and positively with A content at the third codon positions. Nucleotide sequences were also compared between pseudogenes and their functional homologs. The C content of the pseudogenes was lower than that of the functional genes and the A content of the former was higher than that of the latter. Because the synonymous substitution for functional genes and the nucleotide substitution for pseudogenes are exempted from any selective constraint at the protein level, these observations could be explained by a biased pattern of mutation in the Drosophila nuclear genome. Such a bias in the mutation pattern may affect the molecular clock (local clock) of each nuclear gene of each species. Finally, we obtained the average rates of synonymous substitution for three gene groups in Drosophila; 11.0 x 10(-9), 17.5 x 10(-9) and 27.1 x 10(-9)/site/year.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Mol Biol Evol. 1990 Nov;7(6):525-46 - PubMed
    1. Cell. 1982 Jul;29(3):1027-40 - PubMed
    1. Genetics. 1990 Sep;126(1):131-8 - PubMed
    1. Nucleic Acids Res. 1990 Oct 11;18(19):5894 - PubMed
    1. J Mol Evol. 1990 Nov;31(5):402-23 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources