Rate of de novo mutations in the three-spined stickleback

Abstract

Being a fundamentally important genetic parameter and evolutionary force, estimates of germline mutation rates have many uses in evolutionary biology. However, accurate estimates of de novo mutation (DNM) rates are still relatively scarce even for extensively studied evolutionary biology models. We estimated DNM rates for the three-spined stickleback (Gasterosteus aculeatus), the supermodel of ecology and evolutionary biology. Using a large number of family trios sequenced to depth of 45x coverage, we identified 115 unique mutations genome wide and estimated the DNM rate at {micro} = 5.05 x 10-9/bp/gen without any detectable sex bias. The localised DNM rate was found to be positively correlated with recombination rate supporting the notion that recombination is a mutagenic process. Comparison of {micro} and genomic characteristics to those of the related nine-spined stickleback (Pungitius pungitius) revealed a high degree of similarity suggesting that despite 17.5 million years of independent evolution, the mutational processes in the two species appear to have been conserved.