Molecular Evolution Activities
 

This is a comprehensive bibliography (under construction) of primary and secondary sources on the neutral theory of molecular evolution. It currently covers the period 1973-2001.

Author :

Peek, A. S.;Vrijenhoek, R. C.;Gaut, B. S.

Year :

1998

Title :

Accelerated evolutionary rate in sulfur-oxidizing endosymbiotic bacteria associated with the mode of symbiont transmission

Journal :

Molecular Biology and Evolution

Volume :

15

Issue :

11

Pages :

1514-1523

Date :

Nov

Short Title :

Accelerated evolutionary rate in sulfur-oxidizing endosymbiotic bacteria associated with the mode of

Alternate Journal :

Mol. Biol. Evol.

Custom 2 :

ISI:000076888400015

Abstract :

The nearly neutral theory of molecular evolution predicts that the rate of nucleotide substitution should accelerate in small populations at sites under low selective constraint. We examined these predictions with respect to the relative population sizes for three bacterial life histories within chemolithoautotrophic sulfur-oxidizing bacteria: (1) free- living bacteria, (2) environmentally captured symbionts, and (3) maternally transmitted symbionts. Both relative rates of nucleotide substitution and relative ratios of loop, stem, and domain substitutions from 1,165 nt of the small-subunit 16S rDNA were consistent with expectations of the nearly neutral theory. Relative to free-living sulfur-oxidizing autotrophic bacteria, the maternally transmitted symbionts have faster substitution rates overall and also in low-constraint domains of 16S rDNA. Nucleotide substitition rates also differ between loop and stem positions. All of these findings are consistent with the predictions that these symbionts have relatively small effective population sizes, in contrast, the rates of nucleotide substitution in environmentally captured symbionts are slower, particularly in high-constraint domains, than in free-living bacteria.

Notes :

Times Cited: 4 136ZF MOL BIOL EVOL
 -- contributed by John Beatty, March 29, 2002