Rapid evolution of goat and sheep globin genes following gene duplication.

摘要: Statistical analyses of DNA sequences globin genes (beta A, beta C, and gamma) from goat sheep (including new sequence information for the second intron A gamma, kindly provided by A. Davis W. Nienhuis) indicate that rates nonsynonymous substitution in these have been greatly accelerated following gene duplication separating gamma ancestor C C. In both cases acceleration was apparently due to relaxation purifying selection (functional constraints) rather than advantageous mutations because occurred only less important parts chain. The are estimated be about 2.3 x 10(-9) per site year, which is three times higher divergence between human mouse major genes. Our further suggest rate synonymous functional pseudogenes approximately equal 2.8 5.0 introns 3.0 10(-9). time A-beta pair 12 30 million years, respectively. proportion transition 64%, two expected under random mutation but considerably lower 96% animal mitochondrial DNA.