Nonhuman genetics. Strong male bias drives germline mutation in chimpanzees

Germ line mutation determines rates of molecular evolution, genetic diversity and fitness load. In humans, the average point mutation rate is 1.2 x 10^-8 per base pair per generation, with every additional year of father’s age contributing 2 mutations across the genome and males contributing 3-4 times more mutation than females. To assess whether such patterns are shared with our closest living relatives we sequenced the genomes of a nine-member pedigree of Western chimpanzees, Pan troglodytes verus. Our results indicate a mutation rate of 1.2 x 10^-8 per base pair per generation, but a male contribution 7-8 times that of females and a paternal age effect of 3 mutations per year of father’s age. Thus mutation rates and patterns differ between closely related species.