Substitution rates of organelle and nuclear genes in sharks: implicating metabolic rate (again).

摘要: Rates of nucleotide substitution for nuclear genes are thought to be governed primarily by the number germ line replication events (the so-called "generation time" hypothesis). In contrast, rates mitochondrial DNA evolution appear set damage pathways mutation mediated mutagenic by-products oxidative phosphorylation "metabolic-rate" Comparison synonymous estimated cytochrome b gene and nuclear-encoded dlx, hsp70, RAG-1 in mammals sharks shows that molecular approximately an order magnitude slower than those both genes. addition, there is significant positive covariation rate within sharks. These results, interpreted light pervasiveness oxygen metabolism coupled with increasing evidence cross-genome activity repair enzymes, suggest clocks may common mutational mechanisms.