Accelerated evolution and Muller's rachet in endosymbiotic bacteria

摘要

Many bacteria live only within animal cells and infect hosts through cytoplasmic inheritance. These en- dosymbiotic lineages show distinctive population structure, with small population size and effectively no recombination. As a result, endosymbionts are expected to accumulate mildly deleterious mutations. If these constitute a substantial pro- portion of new mutations, endosymbionts will show (i) faster sequence evolution and (ii) a possible shift in base composi- tion reflecting mutational bias.