ISSN:
1432-1432
Keywords:
Synonymous substitution
;
Uniform Rate of Evolution
;
Rapid Evolution of mtDNA
;
Ck Gene of b4 Rabbit
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary For each of eleven different types of nuclear genes, comparisons of the protein coding sequences were made between human, mouse and rat pairwisely, and the evolutionary rate of silent substitution, v S nucl. , was estimated. It is shown that the v S nucl. is not only very high (=5.37×10−9/site/yr), but also approximately uniform for different genes regardless of the types, which confirms our previous results (Miyata et al. 1980b). This is in sharp contrast to the rate of protein evolution which differes greatly from protein to protein. Furthermore the v S nucl. is shown to be approximately constant with respect to different divergence times, at least within a short time period (≤75 Myr). Based on these observations, we propose a new molecular clock which has several advantages over a protein clock. Using this clock, we show that the rate of amino acid replacement in the immunoglobulin Ck gene of b4 rabbit is unexpectedly high, almost comparable to the rate of silent changes. This rate may be the highest one for protein evolution that we know so far. We further examine the rate of silent substitutions in mitochondrial genes comparing mouse and rat. Surprisingly the rate is extremely high (≥35×10−9/site/yr), at least 6-times as high as the corresponding rate of nuclear genes. Based on the estimate, we discuss a possible origin of the rapid rate found in mitochondrial DNA.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02100221
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